How do I know which English word form to use?

This is the second of three lessons about Word Forms. To complete this course, read each lesson carefully and then unlock and complete our materials to check your understanding.   

– Introduce the four word classes relevant to word forms

– Provide examples of useful suffixes for each word class

– Use example sentences to help guide the learner

Lesson 2

Now that we’ve discussed what word forms and word families are and why learning about these topics is important, the next step to word-form proficiency is to understand how to use and recognise the four lexical word classes, which are adjectives, adverbs, nouns and verbs. This lesson deals with this topic precisely, highlighting exactly when such word classes may be needed and which suffixes are most commonly used to form them. If you can first recognise which word class you need to use, you can then select the appropriate suffix to form that word correctly.


1. Adjectives

There are some simple rules that can be followed to determine which word form you need to use in a sentence, and for adjectives this means understanding adjectival distribution. As you may already know, adjectives modify nouns, and as such they may often be found either before the noun or directly after the ‘be’ verb.

Word Forms 2.1 Adjectives Examples

Another way of helping you determine whether you have or require an adjective is to memorise the particular suffixes that are common to this word class. While the following table offers seven of the most common adjectival suffixes, there are still more to watch out for:

Word Forms 2.2 Adjectives Suffixes

2. Adverbs

While adjectives may modify the noun, adverbs unsurprisingly modify the verb. Such adverbs may come before or after the verb they modify and are usually formed using the ‘-ly’ suffix, as is shown in the two examples below.

Word Forms 2.3 Adverbs Examples

However, it’s not always the case that adverbs are formed using ‘-ly’. In fact, some adjectives such as ‘likely’ may use this suffix too, so do be careful here. Unlike adjectives though, there are not so many possible suffixes available to adverbs, and so recognising this word class should be somewhat easier.

Word Forms 2.4 Adverbs Suffixes

3. Nouns

Nouns are the most common word class you’ll use, particularly in academic writing. Thankfully, nouns are easy enough to recognise because they act as the subjects or objects of a sentence, such as in the following two examples:

Word Forms 2.5 Nouns Examples

Much like adjectives, nouns also have a number of common suffixes that a student should learn to recognise. The following table outlines the seven most common:

Word Forms 2.6 Nouns Suffixes

4. Verbs

Verbs are the final word class that you’ll need to watch out for when correctly forming your vocabulary. Verbs indicate what a subject does, feels or believes, and they tend to come immediately after that subject in English (which is a subject-verb-object language) and before any optional or required objects.

Word Forms 2.7 Verbs Examples

What also makes verbs easy to recognise is that this word class may be inflected for person, tense or aspect. The table below shows how the regular verb ‘claim’ may be formed in a variety of ways:

Word Forms 2.8 Verb Conjugation

Clearly then, regular verbs such as ‘claim’ follow the simple pattern shown below:

Word Forms 2.9 Verb Forms

While these formation patterns may make verbs easy to recognise, such variation also makes this word class more difficult to form correctly. This is particularly true of the English language which has many irregular verbs that refuse to follow the standard patterns, two examples of which are shown below:

Word Forms 2.10 Forming Irregular Verbs

The rules provided in this lesson for the distribution of the four lexical word classes should help you to know precisely when to change a word form to improve the grammar of a sentence. The final lesson on this topic however, Lesson 3, then deals with memorising the word families for the most common academic words.

2 of 3 Lessons Completed


Once you’ve completed all three lessons about word, you might also wish to download our beginner, intermediate and advanced worksheets to test your progress or print for your students. These professional PDF worksheets can be easily accessed for only a few Academic Marks.

Our word forms guidance sheet (including all three lessons about this topic) can be accessed here at the click of a button.

Gain unlimited access to our word forms beginner worksheet, with activities and answer keys designed to check a basic understanding of this topic’s lessons.

To check a confident understanding of this topic’s lessons, click on the button below to download our word forms intermediate worksheet with activities and answer keys.

Our word forms advanced worksheet with activities and answer keys has been created to check a sophisticated understanding of this topic’s lessons. 

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