Choosing the Correct Word Form


*The results uncovered some importance differences among the groups.

The sentence above contains a grammatical problem in regards to word form. In particular, the writer uses the noun importance when the adjective important should have been used. We can still understand what this sentence means, but because an incorrect suffix is used, the sentence is ungrammatical. This handout will go through some common suffixes and strategies to help you improve your knowledge of word forms.



In English, there are many words that have the same root, but can be changed to be a verb, noun, adjective, or adverb by adding a suffix. For instance, the root beaut can be used to form a noun beauty, a verb beautify, an adjective beautiful, and an adverb beautifully. To use a word correctly in a sentence, it is important to know two things: not only which part of speech to choose (e.g. noun or verb), but also which suffix creates this part of speech (e.g. -ness or -tion to form a specific noun). This two-stage process can be quite challenging. The table below shows the most common suffixes that are used to create four different parts of speech:







Names a person, place, or thing.


Expresses an action, doing something.


Describes or modifies a noun.


Modifies a verb, adjective, or other adverb.

Common Suffixes:

-tion: education, information

-ity: community, activity

-ty: society, beauty

-er: teacher, reader

-or: behavior, professor

-ar: seminar, singular

-r: computer

-ance: importance

-ness: business

-ism: criticism

-ment: development, treatment

-ent: student, president

-ant: assistant

-ship: relationship

-age: percentage

-ery: discovery

Common Suffixes:

-ize: realize, emphasize

-en: flatten, broaden

-ate: differentiate, initiate

-fy: satisfy, liquefy

-ify: exemplify, beautify

Common Suffixes:

-al: general, social

-ent: independent, confident

-ant: important, dominant

-ive: positive, active

-ous: courteous

-ious: various, obvious

-ate: accurate, private

-ful: useful, beautiful

-less: endless, helpless

Common Suffixes:

-ly is the only common suffix for adverbs:










Some adverbs do not end in -ly (e.g. well, soon, always, here, and hard), while some adjectives can have the ending -ly (early, daily, oily, lonely, and friendly).

Table adapted from Folse, K. S. (2009). Keys to teaching grammar to English language learners: A practical handbook. Ann Arbor: University of Michigan Press.



Strategies for Working on Word Form Issues

- To identify which part of speech should be used in a particular phrase, you could ask yourself whether you need a word that would name an object (noun), express an action (verb), describe an object (adjective), or modify an action or description (adverb).

- Use the table above to identify which part of speech is created with the suffix you used.

- Check words you are unsure about in dictionaries (e.g. Before providing a word definition, dictionaries usually note to which part of speech a given word belongs.

- COCA Word and Phrase ( can be checked to see how a particular word is used in sentences to make sure you have selected the right form.

- Sometimes you know which part of speech to use, but you are not sure which suffix to use (e.g. is it difficultness or difficulty?). Since word suffixes are unpredictable, words can be checked in dictionaries, corpora, or just Googled.

- It is also a good idea to jot down words with the common endings in a notebook while you read for school, work, or pleasure. Then you can return to your notes and look up which part of speech these words are.



Underline correct word forms:

Over the semester, I worked on (purposefully / purpose) crafting questions to elicit, probe, and (connective / connect) students' ideas during a (discuss / discussion). These ideas were presented in our third (classify / class) meeting and reinforced in our readings from Chapin's Classroom Discussions (2003). We talked (explicitly / explicit) about asking questions to elicit students' (initial / initially) thoughts and solutions; asking questions to probe students' answers when the (teacher / teach) does not understand what the (studious / student) is saying, when he or she wants to (verify / verification) that right answers are supported by (correct / correctly) understanding, and when he or she wants to understand the thinking behind an incorrect answer; and supporting students to make (connects / connections) between solutions, methods, models, or mathematical concepts.

The (discussions / discusses) that transpired in my math lesson (reflect / reflective) my ability to skillfully ask (purposeful / purpose) questions when leading a whole-class discussion. In Discussion A, I began by asking students to tell me something they noticed about the Penrose tiling (00:40). By asking a (broadly / broad) question all students could answer, I was able to elicit (initial / initiative) thoughts from many of my students and attend to the learning of all students. Seven students were (ability / able) to contribute their ideas about this (designer / design) and many others had their hands raised. I also used thumbs up or thumbs down and nod your head if… questions to elicit answers from the entire class at once (07:48). This allowed me to get a (sense / sensible) of each student’s thinking, even if he or she was uncomfortable participating in the whole-group discussion.

Practice exercise adapted from Michigan Corpus of Upper-level Student Papers. (2009). Ann Arbor, MI: The Regents of the University of Michigan.
Last updated 10/17/2017