Does This Sentence Actually Work?

Chapter 2

You've had this happen in conversation: someone tells you a long story out loud, and partway through, you realize you've lost track of whether they ever actually finished a sentence, or just kept adding onto it. You weren't confused about the topic. You were unsure whether a specific piece of what they said was ever grammatically complete: did it have an actual subject doing an actual action, or did it just sound like it was going somewhere?

That instinct, checking whether a stretch of words actually finished its own thought, is exactly what this chapter teaches, just applied on paper instead of in conversation. Two close cases show why it's harder than it sounds. The committee, after reviewing every application twice, choosing three finalists sounds complete when read at normal speed, but nothing in it actually asserts that the choosing happened; there's no working verb carrying the action. The manuscript, discovered in a sealed trunk in the attic, was authenticated by three historians sounds almost identical in rhythm, but it is complete, because was authenticated is a real, working verb attached to a real subject. The two sentences feel the same out loud. Only one of them actually works.

Many sentence-structure questions depend on this distinction. It disguises the same basic check, does this stretch of words have a real subject and a real working verb, inside long modifying phrases, inversions, interruptions, and lists, so that the underlying question, which you already know how to answer in conversation, gets harder to spot on the page. ACT groups this family of questions under sentence structure and sentence boundaries, part of the Conventions of Standard English reporting category.

First decide whether the sentence completes its thought.

Many punctuation questions are really clause-structure questions. A comma, a semicolon, and a period are only correct or incorrect relative to what is on each side of them, so the first move is never to judge the mark. It is to read the full sentence, identify what stands on each side of the underlined portion, and ask what kind of unit each side is: a complete clause that could stand alone, or something less than that.

Students who guess at punctuation by ear tend to do fine on short, simple items and fail on the ones built to catch that habit. A comma can sound fine in a sentence and still be wrong, because the ear responds to rhythm and pause, not to grammatical completeness. The test exploits that gap directly.

Before touching any answer choice, isolate the sentence the question lives in. If the sentence is long, find where it would naturally break if you were reading it aloud in two pieces, then check each piece separately: does it have a subject, does it have a working verb, and does it make a complete statement on its own? Only after that check does the punctuation choice become a real decision instead of a guess.

Find the subject and the working verb. Every reliable grammar decision on this test starts from the same two questions: what is the subject doing the action, and what is the verb that carries that action. Skip either question and structural errors become invisible, because the eye naturally fills in meaning even when the grammar has not delivered it.

Finding the subject means finding the noun the sentence is actually about, not the closest noun to the verb. Finding the working verb means finding the word that is doing grammatical work right now, in this clause, not a form that merely resembles a verb.

Take a sentence like The committee, after reviewing every application twice, choosing three finalists. Read quickly, it feels complete. Slow down and isolate subject and verb: the subject is the committee, and the only verb-shaped word attached to it is choosing, which cannot stand as a sentence's main verb by itself. Nothing in the sentence actually asserts that the choosing happened. That single gap is the whole problem, and it is invisible until you go looking for the working verb specifically.

Build the sentence core. The sentence core is the subject and its working verb, stripped of every modifier, phrase, and interruption around them. Practicing this stripping is the fastest way to see whether a sentence is structurally sound, because once description and detail are removed, only the skeleton remains, and a skeleton either holds up a sentence or it does not.

Take The old lighthouse keeper, weathered by decades of storms and solitude, still climbed the spiral stairs every evening. Strip away the modifying material and the core is the keeper climbed. That is a full clause. If instead the sentence read The old lighthouse keeper, weathered by decades of storms and solitude, still climbing the spiral stairs every evening, stripping away the same modifiers leaves the keeper climbing, and climbing alone cannot carry a sentence. The core test exposes the fragment instantly, where reading the whole sentence at normal speed might not.

Tell a complete clause from an incomplete one. A complete clause has a subject and a finite verb and could, if you dropped everything else around it, stand on its own as a sentence. An incomplete clause is missing one of those pieces, or it has been made dependent by a word at its front that signals it cannot stand alone.

Words like because, although, when, while, if, since, and after attach to a clause and immediately make it dependent, no matter how complete the clause looks internally. Because the bridge had been closed for repairs has a subject and a working verb, had been closed, and it is still not a sentence. The word because changes the job that clause is doing: it now sets up a reason, and a reason needs the result attached to it before the thought is finished. The same is true of relative-word openings in certain constructions, where a clause that would otherwise be complete gets folded into a larger sentence instead of standing alone.

The test for completeness, then, has two parts. First, does the group of words have a subject and a finite verb? Second, has anything at the front of that clause turned it into a dependent piece that is waiting for something else? Both questions have to come back clear before you call something a full sentence.

Compare one complete thought with one incomplete thought.

Complete: The bridge had been closed for repairs.

Incomplete: Because the bridge had been closed for repairs.

Nothing changed about the internal grammar between these two. The only difference is the word at the front, and that one word is the entire reason one version is a sentence and the other is a fragment waiting for a second half.

Find the real verb when an -ing word looks active. An -ing form sitting right after the subject reads as active, especially in a long sentence, because -ing words describe motion and the sentence sounds like it is moving. But an -ing word standing alone, without a helping verb like is, was, were, or had been in front of it, cannot serve as a clause's main verb. It functions instead as a participle, a description, not an assertion.

The same caution applies to an infinitive, the to plus base-verb form. The team hoping to finish before the deadline and the team wanting to finish before the deadline both feel like they are reporting something happening, but neither one actually asserts anything. Add a real finite verb, was hoping or had wanted, and the clause becomes able to stand on its own.

An -ing form can look like a verb without completing the sentence.

Fragment: The engineer reviewing the blueprints late into the night, searching for the miscalculation that had delayed the project by weeks.

Repair: The engineer reviewed the blueprints late into the night, searching for the miscalculation that had delayed the project by weeks.

Changing reviewing to reviewed supplies the one thing the sentence was missing: an actual finite verb asserting that the review happened. Searching can stay as a participle describing how the engineer worked, because the sentence now already has its main verb elsewhere.

Fix a fragment by restoring the missing structure. Once a fragment is identified, the fix is almost always one of two moves: give the clause a finite verb it is missing, or connect it to the independent clause nearby that it was always meant to attach to. Which move is correct depends on what the fragment actually needs, not on which answer choice looks shortest.

If the fragment is missing a working verb, as in the lighthouse-keeper example, a helping verb restores it: the keeper was still climbing instead of the keeper still climbing. If the fragment is a dependent clause with a complete verb, attach it to an independent clause. A dependent clause that comes first is normally followed by a comma. When it comes second, punctuation depends on its function and meaning: many essential adverb clauses take no comma, while nonessential or strongly parenthetical material may be set off.

A student who reflexively adds a comma to every fragment will fix some errors and create new ones. The repair has to match the specific gap: a missing verb needs a verb, and a dependent clause with a nowhere-to-attach problem needs a connection, not a new verb form.

Then decide how complete thoughts should be joined.

Two independent clauses standing next to each other need one of a small number of legitimate boundaries between them: a period, a semicolon, or a comma paired with a coordinating conjunction such as and, but, or, so, yet, for, or nor. A comma by itself is not one of the legitimate options, no matter how short or closely related the two clauses are.

Joining two independent clauses with only a comma produces a comma splice. It is one of the most common errors on this test because it often sounds acceptable out loud, especially in the kind of casual, conversational sentence pairs the test likes to use. I checked the schedule twice, the meeting had already been moved. Read at speaking speed, the comma feels like a natural breath. Grammatically, it joins two complete statements with nothing strong enough to hold them together.

A comma cannot join two complete thoughts by itself.

The interview went well, she still worried about the second round.

This is a splice because both sides are independent clauses, the interview went well and she still worried about the second round, and nothing but a comma sits between them. A period, a semicolon, or comma + but would each correctly mark the boundary; a comma alone cannot.

A sentence can sound natural and still be a run-on.

He said he'd call after the flight landed, he never actually did and by the time anyone thought to check, three hours had already passed.

This one is easy to miss because the sentence keeps moving and sounds like ordinary speech rather than a textbook error. But the first comma still joins two independent clauses, he said he'd call after the flight landed and he never actually did and by the time anyone thought to check, three hours had already passed, with nothing but a comma between them. The length and the casual tone are exactly what make it a realistic hard case: nothing about how it sounds signals the problem, so the fix has to come from checking clause structure directly rather than from how the sentence reads.

Keep one subject with two actions together. A comma before and is often unnecessary in a specific, recognizable pattern: when one subject performs two actions joined by and, the two verb phrases form a compound predicate. On ACT-style sentence-boundary questions, a compound predicate normally takes no comma before the conjunction; first check whether a new subject begins after the conjunction.

The chef prepared the sauce and plated the dessert has one subject, the chef, doing two things. No comma belongs before and. Compare that with The chef prepared the sauce, and the server plated the dessert, where the second half has its own subject, the server, making it a full independent clause that does need the comma.

The trap gets harder when the first verb phrase is long, because by the time a reader reaches the and, the original subject feels far away and the second verb phrase can start to look like it belongs to a new clause.

One subject doing two actions usually needs no comma before and.

The negotiating team spent nearly six months drafting, revising, and quietly renegotiating the terms of the contract, and ultimately presented a final version to both companies' boards.

Even though a great deal happens between the subject and the second verb, there is still only one subject, the negotiating team, performing two actions: spent and presented. The comma before and is not justified, because nothing after it introduces a new subject; it is the same team still acting.

Use subordination to show which idea depends on the other. Subordinating conjunctions like because, although, while, since, and when do more than join two clauses. They tell the reader which idea is the main point and which idea is supporting or contrasting information. Choosing the wrong subordinator, or choosing a coordinating conjunction when a subordinating relationship is what the sentence actually needs, changes what the sentence claims about the relationship between its two ideas.

Although the forecast predicted rain, the game continued as scheduled signals a contrast: rain was expected, but it did not stop the game. Swap although for because and the sentence claims the opposite relationship, that the rain caused the game to continue, which does not make logical sense. The grammar of both versions is fine. Only one of them expresses the relationship the sentence is actually describing.

Choosing a conjunction by how it sounds, without checking what logical relationship the two clauses actually have, is one of the most common ways students lose these points even when their sentences are grammatically well formed.

Check a long sentence one clause at a time. Long ACT sentences are built to overwhelm a single read-through. The reliable approach is to break the sentence into its individual clauses, mark where each one starts and ends, and evaluate each piece on its own before deciding whether the connections between them are legitimate.

Take a sentence with three clauses stacked together: an opening dependent clause, a short independent clause, and a second independent clause tacked onto the end. Read as one long unit, it is easy to lose track of where one clause ends and the next begins, and that is exactly where errors hide. Read clause by clause, each boundary becomes a specific, checkable decision: complete or incomplete, joined correctly or not.

This approach becomes essential once you reach mixed practice, where a sentence's punctuation and its subordination choices interact within the same long structure. Slowing down to identify each clause is not extra work; it is the only way to see the sentence's actual structure instead of its surface rhythm.

Let the answer choices expose the boundary. On many boundary questions, the choices vary punctuation while leaving most of the wording unchanged. That pattern can reveal which boundary the item is testing. Reading across the choices before picking one shows exactly what kind of boundary the question is testing: a period versus a comma, a semicolon versus a comma and conjunction, or a comma alone versus no punctuation at all.

If two of the four choices produce a comma splice and only differ in a swapped word or an added and, that comparison confirms the boundary is the actual issue being tested, and rules out choices that fail to fix it regardless of their other changes. Reading the choices as a set, rather than testing them one at a time from the top, often reveals the structural pattern the question is built around.

Keep every description next to what it describes.

A modifier has to sit close enough to the word it describes that no other reading is possible. When a modifying phrase is placed carelessly, the sentence can end up describing the wrong noun, even though every individual word is used correctly.

Covered in dust, Maria found the old photograph album in the attic. Read literally, this sentence says Maria was covered in dust, not the album. The intended meaning is almost certainly the reverse, but grammar does not run on intended meaning; it runs on proximity and structure. The modifier attaches to whatever noun immediately follows it, and here that noun is Maria.

The fix is to move the modifier next to the word it should describe, or to give the modifier its own subject: Maria found the old photograph album, covered in dust, in the attic, or Covered in dust, the old photograph album sat waiting for Maria to find it. Either repair puts the description next to the thing being described.

Let an opening modifier point to the subject that follows. An opening modifier, a phrase set off by a comma at the start of a sentence, is a specific and heavily tested version of the modifier-attachment problem. Whatever noun comes immediately after that opening comma is treated, grammatically, as the thing the modifier describes. If the actual subject of the sentence is something else, the sentence has a dangling modifier, and no amount of clear intended meaning fixes it.

An opening description must point to the subject that follows.

Having practiced the routine for months, the recital felt effortless to the dancers.

The opening phrase describes practicing, an action a person does, but the noun right after the comma is the recital, which cannot practice anything. The subject needs to be the dancers themselves: Having practiced the routine for months, the dancers found the recital effortless.

Clear intended meaning does not rescue a dangling modifier.

Exhausted after the twelve-hour shift, the coffee did nothing to keep him awake.

Everyone reading this sentence understands that the person, not the coffee, was exhausted. That obviousness is exactly what makes the error easy to miss. Grammatically, the coffee is what the opening phrase attaches to, and coffee cannot be exhausted. The repair puts the person in the subject slot: Exhausted after the twelve-hour shift, he found that the coffee did nothing to keep him awake.

Move a modifier to the word it actually describes. Not every misplaced modifier sits at the front of the sentence. A modifier in the middle or end of a sentence can drift toward the wrong noun just as easily, especially when several nouns are competing for the reader's attention nearby.

She served sandwiches to the guests wrapped in plastic wrap. As written, the phrase wrapped in plastic wrap sits closest to the guests, which produces an unintended and slightly absurd reading. Moving the modifier next to sandwiches, the noun it is actually meant to describe, resolves the ambiguity: She served sandwiches wrapped in plastic wrap to the guests.

The general principle carries across every version of this error: identify what the modifier is logically meant to describe, then check whether it is physically next to that noun in the sentence. If it is not, moving it, not rewording it, is usually the fix.

Keep a relative clause beside the noun it identifies. A relative clause, one that begins with who, whom, whose, which, or that, identifies or adds information about the noun it follows. When two plausible nouns sit near the relative clause, the clause is read as describing whichever one is closer, which can create a sentence that technically makes an odd or unintended claim.

Keep a who, which, or that clause beside the noun it describes.

The reporter interviewed the assistant of the scientist who had won the award.

As written, who had won the award most naturally attaches to the scientist, but the sentence becomes ambiguous if the writer intended the assistant to be the award winner. The repair should remove that ambiguity rather than rely on proximity alone: The reporter interviewed the scientist's assistant, who had won the award. Relative-clause placement is strongest when the intended antecedent is unmistakable.

Correct use of who versus that, and correct case for who versus whom, matter here too, but the core skill being tested is almost always placement: does the relative clause sit next to the one noun it is grammatically allowed to modify, with no plausible competing noun in between.

Make the subject, verb, tense, and pronoun fit the sentence.

A phrase, a parenthetical, or an entire second clause can sit directly between a subject and its verb, and whatever noun is closest to the verb at that point often wins the reader's ear, even when it is not the true subject. Finding the sentence core through an interruption means locating the subject and verb correctly despite whatever sits between them, and it is the skill behind several related question types: subject-verb agreement, verb form and tense, and pronoun agreement all depend on first identifying the true subject correctly.

Ignore the noun inside the interruption and match the real subject.

The collection of vintage postcards, carefully preserved by three generations of the same family, remain in remarkably good condition.

The verb remain has drifted into agreement with postcards, the plural noun sitting right before the long modifying phrase. The true subject is the collection, singular, so the verb should be remains. The intervening phrase, however long, does not change what the subject actually is.

Inversion produces the same trap from a different direction: when the verb comes before the subject, as it does after phrases like there or in certain questions and emphatic constructions, it is easy to agree the verb with the nearest noun rather than searching ahead for the real subject.

When the verb comes first, look ahead for the real subject.

Sitting on the highest shelf of the old library was several leather-bound volumes that no one had opened in decades.

The verb was appears before its subject, which is actually several leather-bound volumes, plural. The correct verb is were. Reordering the sentence mentally, several leather-bound volumes were sitting on the highest shelf, makes the true subject and its correct verb form obvious.

Indefinite pronouns create a related but distinct trap. Words like each, everyone, and neither are always grammatically singular, even when they are followed by a plural phrase describing a group. A few others, including none, some, all, and most, are not fixed either way: their number depends on the noun they refer to, singular when that noun is singular or uncountable, plural when it is plural. None of the cake was eaten takes a singular verb because cake is uncountable; none of the cookies were eaten takes a plural verb because cookies is plural. The reliable move is to check which specific pronoun is at work, not to assume every indefinite pronoun behaves the same way.

Words like each and everyone stay singular.

Each of the applicants who submitted their portfolios before the deadline were given priority scheduling for interviews.

Each is one of the pronouns that stays singular regardless of what follows it, and it remains the true subject regardless of the plural noun applicants sitting inside the prepositional phrase that follows it. The correct verb is was given, not were given. The of-phrase describes a group the subject is drawn from; it does not change each's own number.

Verb form and tense follow the same logic of not trusting surface signals. Two past actions do not automatically require past perfect. Use past perfect when the writer needs to place an earlier action or state before another past reference point, or when that relationship is important to the sentence's emphasis.

Use past perfect only when the earlier action needs to be marked.

By the time the fire department arrived, the warehouse had already been burning for nearly an hour.

Had been burning is appropriate because the sentence presents the fire as an ongoing condition that began before and continued up to the arrival. Was already burning can also be grammatical; the difference is aspect and emphasis, not basic chronological clarity. Compare that with a sentence where two past actions are simply reported side by side with no ambiguity about their order, such as She finished the report and sent it to her manager; there, past perfect would be an unnecessary addition, because nothing about the sequence needs clarifying.

Irregular participles create a narrower but reliably tested version of the same verb-form issue.

After had, use the past participle form.

Had the committee not spoke up during the review, the error would have gone unnoticed until the final audit.

The past participle of speak is spoken, not spoke. In this construction, after had, the sentence needs the participle form: Had the committee not spoken up. Relying on how the simple past sounds, rather than checking the actual participle form, is what makes irregular verbs a durable source of errors even for otherwise strong writers.

Pronoun agreement and reference belong in this same family of checks, because a pronoun's job is to point back clearly to the noun that governs both its number and its identity, and an interruption or a second nearby noun can obscure that link exactly the way it obscures subject-verb agreement.

Name the person when a pronoun could point to two people.

When Sarah handed the manuscript to her editor, she pointed out several unresolved plot threads.

She could grammatically refer to either Sarah or the editor, and both readings are plausible. The sentence needs to be rewritten so the pronoun's antecedent is unambiguous, for instance by naming the person directly: When Sarah handed the manuscript to her editor, the editor pointed out several unresolved plot threads.

A pronoun still needs one clear antecedent in the earlier sentence.

The city council reviewed three separate proposals for the new transit line last spring. It was ultimately rejected after months of public hearings.

It is singular, but the only available antecedent, three separate proposals, is plural, and it is unclear which single proposal, if any, it is meant to refer to. The fix requires naming the specific proposal directly rather than relying on a pronoun that has no clear singular antecedent to point back to.

Find the passage's time frame before choosing a tense. Some tense and voice questions cannot be solved from the underlined sentence alone; the correct form depends on a time frame, a narrating perspective, or a pronoun person established one or more sentences earlier. Before choosing, identify the dominant tense the surrounding sentences are already using, and check whether anything specific, a date, a completed event, a general truth, justifies departing from it. A passage narrating history in the past tense does not require every single verb to stay in the past: a sentence stating a present-day general truth can legitimately shift to the present tense, and a sentence describing a specific completed study or event can legitimately use the past even inside an otherwise present-tense explanation. The task is not mechanical matching; it is identifying whether a shift is earned by the sentence's own content or is simply an unmotivated drift.

Match the passage time frame unless the meaning requires a shift.

The excavation team spent three seasons clearing the site. By the second season, they had catalogued more than four hundred artifacts, and researchers today continue to study the collection at a regional museum.

The underlined verb continue correctly shifts to the present tense, even though the surrounding sentences narrate the excavation in the past, because the sentence describes an ongoing, present-day state, researchers still studying the collection now, not a further event in the excavation's own past timeline. Changing it to continued would incorrectly fold a present-day fact into the completed narrative.

Voice works the same way: a shift between active and passive is only a problem when it obscures who is doing what or breaks a pattern of emphasis the paragraph has deliberately established, not simply because both forms are grammatically available. A paragraph that has been consistently naming its subject as the actor across several sentences, and then shifts unnecessarily to a passive construction that drops that actor, has broken something the reader was relying on. A paragraph with no such established pattern can use either voice without a real error existing at all.

Pronoun person follows the same logic. Once a passage establishes whether it speaks in first person, second person, or a general third person, an unmotivated shift, sliding from I or we into you, or from one or people into you, breaks a pattern the reader has already been trained to expect, even though every individual sentence remains grammatically correct on its own.

Do not switch from I, one, or people to you without a reason.

Ever since I started keeping a research journal, I've noticed patterns in my own thinking that would otherwise go unrecorded. You begin to see which questions you return to again and again.

The passage opens in first person, I, and the underlined sentence's shift to you has no rhetorical justification, no direct address to a reader is being set up elsewhere in the passage; it is simply a drift. The correct revision preserves the established person: I begin to see which questions I return to again and again.

Use earlier time markers to choose the tense.

The observatory recorded unusually faint signals throughout 2019, and analysis of that data eventually confirmed the presence of a previously undetected companion star. Researchers ___ the finding at a conference the following year.

Both announce and announced are grammatically well-formed verbs in isolation, and only one fits: the passage has already anchored the finding to a specific past sequence, faint signals in 2019, then confirmation, then a conference "the following year," so the announcement itself is a further event in that same completed timeline, not a present-day report. Announced is correct; announce would incorrectly detach the conference from the sequence the earlier sentences already established.

Make joined ideas use the same grammatical form.

Items that perform the same grammatical role in a series or paired construction should use parallel grammatical forms. A sentence that lists a noun, a gerund, and an infinitive in the same series has broken parallelism, even if every individual item makes sense on its own.

Make every item in a series use the same grammatical form.

Her weekend routine included cleaning the apartment, grocery shopping, and to catch up on reading.

The series mixes two gerunds, cleaning and shopping, with an infinitive, to catch up. Matching all three to the gerund form fixes it: cleaning the apartment, grocery shopping, and catching up on reading.

Parallelism is a structural requirement, not a stylistic preference. The test rewards recognizing the mismatch quickly, by scanning a series for its grammatical form rather than reading for meaning alone, since the meaning of a mismatched series is usually still perfectly clear.

Keep paired ideas in the same grammatical shape. Correlative constructions such as not only/but also, either/or, and both/and impose the same requirement as a simple series: whatever grammatical form follows the first half of the pair has to match the form following the second half.

The proposal was praised not only for its ambition but also because it was affordable. The first half of the pair is followed by a prepositional phrase, for its ambition; the second half is followed by a clause, because it was affordable. Matching the forms fixes it: not only for its ambition but also for its affordability.

Long series and paired constructions test the same underlying skill as a short list; the only added difficulty is that more material sits between the pieces that need to match, which makes it easier to lose track of the form each one is supposed to take.

Do not let different wording lengths hide the same structural mismatch. The hardest parallelism items disguise a grammatical mismatch inside items of very different length, so that a quick scan for matching shapes does not immediately reveal the problem. A student checking only whether the items feel similar in weight or importance can miss a mismatch that is purely about grammatical form.

Long lists still need matching grammatical forms.

The renovation plan called for reinforcing the foundation, a complete rewiring of the electrical system, and to replace every window on the building's south-facing side.

Three items are joined by and: a gerund phrase, reinforcing the foundation; a noun phrase, a complete rewiring of the electrical system; and an infinitive phrase, to replace every window. All three need to match. Converting everything to the gerund form fixes the series: reinforcing the foundation, completely rewiring the electrical system, and replacing every window on the building's south-facing side.

Use a structural check rather than a sound test: isolate each coordinated item, identify its grammatical role or phrase type, and confirm that parallel items use matching structures. Do not rely only on the first word.

Combine the sentence checks without labels.

The final stretch of ACT English questions on any given passage rarely announces which rule is being tested. A single paragraph can contain a boundary error, a modifier problem, and an agreement slip within a few sentences of each other, and the only way through is the same process used throughout this chapter: find the sentence core first, check what stands on each side of any punctuation, and confirm every modifier sits next to the word it describes.

Apply the chapter skills without being told which rule is tested.

The archive, digitized over the course of eighteen months by a small team of volunteers, contain nearly forty thousand photographs. Each of the images, along with their original captions, were catalogued by decade. Working late into most evenings, the project's deadline still felt impossibly close to the volunteers, and they pushed to finish it anyway.

Three separate mechanisms are at work here. In the first sentence, the subject is the archive, singular, so the verb should be contains, not contain; the long modifying phrase between subject and verb is the distraction. In the second sentence, the subject is each, an indefinite pronoun that stays singular regardless of the plural phrase beside it, so the verb should be was catalogued, not were catalogued. In the third sentence, the opening modifier working late into most evenings describes the volunteers, but the noun immediately following the comma is the project's deadline, which cannot work late into an evening; the sentence needs the volunteers in the subject position, as in Working late into most evenings, the volunteers still found the project's deadline impossibly close, and they pushed to finish it anyway.

Name both sides before choosing the mark, name the true subject before choosing the verb, and name the noun a modifier actually describes before deciding the sentence is correct as written. Those three habits, applied in order, resolve nearly everything this chapter has covered.

Practice Set: English Sentence Foundations

Each question below tests one mechanism from this chapter. Read the full sentence before choosing an answer, and identify the specific reason each wrong choice fails, not just why the key is right.