HESI A2 Grammar cheat sheet

A complete sentence needs a subject, a finite verb, and a complete thought; a fragment lacks one of these, as in "Because the lab closed early" (dependent clause only) or "Running down the hall" (no subject).

Comma splice: two independent clauses joined only by a comma. Fix by adding a coordinating conjunction (FANBOYS: for, and, nor, but, or, yet, so), replacing the comma with a semicolon, or splitting into two sentences.

Run-on (fused sentence): two independent clauses with no punctuation at all; correct with a period, semicolon, or comma plus coordinating conjunction - not with a comma alone.

A semicolon joins two independent clauses or items in a complex list; a colon follows a complete clause and precedes a list, explanation, or quotation. Never place a colon between a verb and its object or between a preposition and its object.

Nonessential (nonrestrictive) clauses and appositives take commas: "My sister, who lives in Ohio, is a nurse." Essential clauses take no commas: "The woman who lives next door is a nurse."

Use commas after introductory elements, between items in a series, between coordinate adjectives (test: can you insert "and"?), and around parenthetical interrupters; do not use a comma to separate subject from verb.

Subject-verb agreement: the verb matches the true subject, not an intervening phrase ("The box of files is heavy"). Compound subjects joined by "and" take plural verbs; those joined by "or/nor" agree with the nearer subject.

Indefinite pronouns: each, either, neither, everyone, everybody, anyone, nobody, someone are singular ("Everyone is here"); both, few, many, several are plural; some, all, most, none may be singular or plural depending on the noun they refer to.

Pronoun case: use subject forms (I, he, she, they, who) for subjects and after linking verbs in formal usage; object forms (me, him, her, them, whom) for objects of verbs and prepositions. In comparisons, complete the clause: "She is taller than I [am]."

Verb tense consistency: keep tenses logical within a sentence; use past perfect (had + participle) for the earlier of two past actions and present perfect (has/have + participle) for action continuing to or relevant at the present.

Dangling modifier: an introductory participial phrase must describe the subject of the main clause. Wrong: "Walking to class, the rain began." Right: "Walking to class, I felt the rain begin."

Misplaced modifier: place limiting words (only, almost, nearly, just) immediately before the word they modify; "She only ate salad" differs from "She ate only salad."

Parallel structure: items in a series, and elements joined by correlative conjunctions (either...or, not only...but also, both...and), must share the same grammatical form.

Commonly confused pairs: affect (verb, to influence) vs. effect (noun, result); lie (to recline) vs. lay (to place something); its (possessive) vs. it's (it is); their (possessive) vs. they're (they are) vs. there (place); your vs. you're; then (time) vs. than (comparison); fewer (countable) vs. less (mass).

Apostrophes: add 's for singular possessives (the nurse's chart) and for plural nouns not ending in s (the children's ward); add only an apostrophe for plural nouns ending in s (the nurses' station). Do not use apostrophes for simple plurals or possessive pronouns (hers, ours, its).

Capitalization: capitalize proper nouns and adjectives, the first word of a sentence, titles before names, days, months, and languages; do not capitalize seasons, general academic subjects (except language names), or titles after names used descriptively.

Who vs. whom: who is the subject (who called?), whom is the object (whom did you call? / to whom). Whose is possessive; who's means who is.

Modifier and comparison errors: use -er/more for two items and -est/most for three or more; avoid double comparatives ("more better") and double negatives ("can't hardly"); ensure comparisons are complete and logical ("like" takes a noun, "as" takes a clause).