English and Language Usage: Sentence Boundaries, Agreement, and Punctuation
This section tests standard written English: grammar, punctuation, sentence structure, and word choice. Most items hinge on a single rule, so learn to name the rule the question is testing.
Core concepts
A sentence fragment lacks a subject, a verb, or a complete thought; a run-on or comma splice joins two independent clauses without correct punctuation - fix them with a period, a semicolon, or a comma plus a coordinating conjunction (and, but, or, nor, for, so, yet). Subject-verb agreement requires matching singular subjects to singular verbs, and interrupting phrases never change the subject. Pronouns must agree with their antecedents in number and gender and use the correct case (subject, object, possessive). Keep verb tense consistent, place modifiers next to what they describe (avoid dangling modifiers at the start of a sentence), and maintain parallel structure in lists. Know your punctuation: commas for introductory elements and nonessential information, semicolons between related independent clauses, colons before lists or explanations, apostrophes for possession (never for simple plurals), and its versus it's. Watch commonly confused pairs: affect/effect, their/there/they're, then/than, and between you and me.
Traps
Prepositional phrases hiding the true subject, indefinite pronouns such as each, everyone, neither (singular), collective nouns, compound subjects joined by or, and apostrophes inserted into plural nouns.
Rule of thumb
Find the verb, then cross out every prepositional phrase between it and its subject before deciding singular or plural.
Worked example: "The box of markers (was/were) on the shelf." Cross out of markers; the subject is box (singular), so the answer is was. Likewise, "Each of the students has a badge" - each is singular.