ACT English: Word Form Rules

Many words can take on several different grammatical forms. For instance, the word grammar itself can be a noun (grammar), an adjective (grammatical), or an adverb (grammatically). There are also some words that have noun, adjective, adverb, and verb forms. Word forms can also change for reasons related to tense and singular/plural variation.


ACT English is very conscious of these varying word forms and you’ll get a lot of questions that deal with the proper formation of words. Here are some grammar rules to remember as you keep an eye on word forms in the English portion of the exam.


Adjectives Modify Nouns & Adverbs Modify Verbs

ACT English often tests your ability to distinguish between adjectives and adverbs. For example, you might see a sentence that says “What I love the most about my favorite restaurant its fast, politely service.” Can you see the mistake? Service is a noun, but politely is an adverb, so you’ll want to look for an answer choice that changes politely to polite. A similar ACT English sentence might say something like “The staff at the restaurant serve me very polite.” In that case, you need to change the adjective polite to adverb politely, so it can correctly describe the verb serve.


An Ending of “ly” Usually Means that the Word Form is an Adverbs… But Not Always!

This is a small rule that can trip you up if you scan a passage a little too quickly. Yes, many words with “ly” at the end are adverbs, including quickly from the previous sentence, but there are also some common “ly” words that are not adverbs. Scholarly is an adjective. Monopoly is a noun. Multiply is a verb.

There are other exceptions too. If you take a careful look at any of these in the text, you can immediately know their grammatical function. Scan carefully so that you don’t make any mistakes as you answer the questions.


The Verb and Noun Forms of a Word are Usually Different

Some words don’t change when they become a verb or noun. You can take a test, or you can test someone’s knowledge. More often the word form does change when the grammar function switches between noun and verb. Compute (verb) becomes computation (noun), assess (verb) becomes assessment (noun), and so on.


The Takeaway

Words in written English often contain small but very important differences. If you miss these differences on the ACT, it will hurt your score. For a top score, teach yourself to notice these differences and recognize correct word forms quickly.



  • David Recine

    David is a Test Prep Expert for Magoosh TOEFL and IELTS. Additionally, he's helped students with TOEIC, PET, FCE, BULATS, Eiken, SAT, ACT, GRE, and GMAT. David has a BS from the University of Wisconsin-Eau Claire and an MA from the University of Wisconsin-River Falls. His work at Magoosh has been cited in many scholarly articles, his Master's Thesis is featured on the Reading with Pictures website, and he's presented at the WITESOL (link to PDF) and NAFSA conferences. David has taught K-12 ESL in South Korea as well as undergraduate English and MBA-level business English at American universities. He has also trained English teachers in America, Italy, and Peru. Come join David and the Magoosh team on Youtube, Facebook, and Instagram, or connect with him via LinkedIn!

By the way, Magoosh can help you study for both the SAT and ACT exams. Click here to learn more!


No comments yet.

Magoosh blog comment policy: To create the best experience for our readers, we will only approve comments that are relevant to the article, general enough to be helpful to other students, concise, and well-written! 😄 Due to the high volume of comments across all of our blogs, we cannot promise that all comments will receive responses from our instructors.

We highly encourage students to help each other out and respond to other students' comments if you can!

If you are a Premium Magoosh student and would like more personalized service from our instructors, you can use the Help tab on the Magoosh dashboard. Thanks!

Leave a Reply