Grammar Foundations

What you'll learn

• Identify nouns, verbs, adjectives, adverbs, pronouns, prepositions, conjunctions, and interjections
• Distinguish between independent and dependent clauses
• Recognize simple, compound, complex, and compound-complex sentences
• Understand how sentence structure errors appear on the ACT
• Identify the six main verb tenses (simple present/past/future and present/past/future perfect)
• Maintain consistent verb tense within a passage and recognize when tense shifts are intentional
• Spot the ACT's favorite verb traps: past-tense vs. past-participle forms (went/gone, saw/seen, drank/drunk) and 'would have' (never 'would of')

Key concepts

Every English sentence contains at least a subject (noun or pronoun) and a predicate (verb). An independent clause expresses a complete thought and can stand alone; a dependent clause begins with a subordinating conjunction (because, although, when) or relative pronoun (who, which, that) and cannot stand alone. Verb tense is one of the most tested grammar concepts on the ACT (~10% of grammar questions). The six key tenses are: simple present ('she runs'), simple past ('she ran'), simple future ('she will run'), present perfect ('she has run'), past perfect ('she had run'), and future perfect ('she will have run'). The ACT tests whether you can maintain consistent tense within a paragraph and recognize when a shift is appropriate; the default is to match the surrounding tense unless the passage signals a real change in time. Past perfect ('had run') is used to mark an action that finished before another past action, so an earlier event in a flashback often calls for it, but do not force past perfect onto every past-tense sentence. Watch the highest-yield verb traps: the past tense and past participle are different forms (she went vs. she has gone, I saw vs. I have seen, they drank vs. they had drunk), and 'would have' is always written that way, never 'would of.' Progressive forms ('was running') describe an ongoing action, while perfect forms ('has run') tie a past action to the present, so do not swap one for the other. ACT English questions fall into three reporting categories: Conventions of Standard English (grammar, usage, punctuation), Production of Writing (organization, transitions, relevance), and Knowledge of Language (concision, word choice, tone). The enhanced ACT deliberately shifted weight toward Production of Writing and Knowledge of Language, so do not treat English as mostly a grammar test. Understanding how words function still matters for spotting errors quickly, but budget real practice for the rhetoric and clarity questions too.

Pro tips

• When in doubt, find the main verb first, then find its subject. Many ACT traps separate the two with long phrases.
• Read each sentence in your head to hear whether it sounds complete; fragments and run-ons often 'feel' wrong even before you can name the rule.
• Keep a running list of grammar terms you are shaky on and review it before each study session.
• Drill verb forms directly: for every underlined verb, check tense consistency with the surrounding sentences, watch would/will conditionals, and confirm the right gerund vs. infinitive ('enjoy running,' not 'enjoy to run'; 'want to run,' not 'want running').