ACT English Grammar Rules

A collection of grammar, punctuation, and usage rules commonly tested on the ACT English subtest.

Its vs. It’s

'Its' is possessive while 'it’s' is a contraction for 'it is'; 'its’' does not exist.

Then vs. Than

'Then' is typically used for time or sequencing, while 'than' is used for comparisons.

There vs. Their vs. They’re

'There' refers to a place, 'their' is possessive, and 'they’re' is a contraction for 'they are'.

Who’s vs. Whose

'Who’s' is the contraction for 'who is', and 'whose' is the possessive form.

Affect vs. Effect

Two commonly confused words where 'affect' is typically used as a verb and 'effect' as a noun.

Laying vs. Lying

Two distinct verbs often confused in usage and tense.

Began vs. Begun

Different forms of the same verb involving specific tenses and the use of helping verbs.

Who vs. Whom

Grammar rule that can be solved by utilizing replacements with 'he' or 'him'.

Independent Clauses

A group of words that contains a subject and a verb and can stand alone as a complete sentence.

Dependent Clauses

A group of words that contains a subject and a verb but cannot stand alone as a complete sentence.

Methods for Separating Independent Clauses

Independent clauses can be separated using a period, a semicolon, or a comma combined with a conjunction.

FANBOYS

An acronym for coordinating conjunctions used with commas to separate independent clauses.

Separating Independent and Dependent Clauses

A comma is used to separate these two different types of clauses.

Commas between Adjectives

Punctuation used to separate multiple descriptors for a noun.

Colons

Punctuation used for introducing lists and explanations.

Dashes

Punctuation marks that are equal to colons or used to offset nonessential phrases.

Nonessential Phrases

Phrases offset by commas or dashes that do not include names.

Subject-Verb Agreement

The rule that a subject and its verb must both be singular or both be plural.

Verb Tenses

The form of a verb that indicates the time of an action or state of being.

Parallelism

The requirement that parts of a sentence are grammatically consistent or similar in construction.