IELTS Vocabulary: How to Choose the Right Word Form

Choosing the right form of a word is essential for clear and accurate communication.  

If you want to achieve a high score in your IELTS Writing and Speaking tests, it’s also important to use a variety of words. Using a range of word forms shows the examiner that you can vary your sentences and use English more flexibly.  

In the IELTS Listening and Reading tests, you also need to understand how different types of words work together in a sentence. For tasks like summary completion, checking the words around the missing answer can help you decide if you need a noun, verb, adjective, or adverb. 

In this article, we’ll take you through the basics of word formation in English, look at some common mistakes to avoid and finish with our top tips for choosing the right words. 

Before we get started, let’s see what you already know. Look at the word families below. Can you fill in the missing words? 

The form of a word in English changes depending on what you want to express. There are many reasons why you might need to change a word form. Here are a few examples:  

Verb tense: work (infinitive), worked (past simple)  

Subject-verb agreement: I work (first person), She works (third person) 

Singular or plural: child (singular), children (plural) 

Comparison: fast (adjective), faster (comparative), fastest (superlative) 

Word class: encourage (verb), encouragement (noun), encouraging (adjective) 

In this article, we’ll focus on changes to word class. 

The form a word takes depends on the way it is used in a sentence. We call this its grammatical function or part of speech.  

Let’s look at some common examples: 

Noun: a person, a place or an object. Nouns can also be ideas, qualities, feelings and events. (Examples: student, river, cup, freedom, beauty, sadness, festival) 

Verb: describes an action or a state of being.  (Examples: walk, sleep, climb, feel, know, be) 

Adjective: describes a noun or a pronoun. (Examples: beautiful, high, green, interesting)  

Adverb: describes or gives more information about a verb, an adjective, another adverb or a phrase. 

(Examples: beautifully, slowly, quite, often, early, unusually, everywhere, fortunately).  

Imagine you want to take the verb create and make it the subject of sentence to talk about a process or concept.  

You will need to change the part of speech from a verb to a noun. Create (verb) becomes creativity (noun). 

Example sentence: Creativity helps organisations adapt to new trends and technologies. 

If we want to use it to describe something (e.g. creative thinking), we need to change the word form to an adjective. 

Creative thinking can help organisations adapt to new trends and technologies. 

If we want to use this word to describe how something is done (e.g. thinking creatively), we need to change the word form to an adverb. 

Thinking creatively can help organisations adapt to new trends and technologies. 

From spelling to pronunciation to irregular forms, here are a few things you need to watch out for when you’re forming new words.  

Spelling  

In English, some nouns and verbs have similar spellings with only a slight change to one or two letters. 

Example: advice and advise

The doctor advised him to cut down on sugary foods. (verb) 

Her teacher gave her some useful advice on how to improve her reading skills.  (noun) 

Tip: Allow time at the end of your Writing test to check your responses for spelling and grammar mistakes.  

Pronunciation 

Other nouns and verbs have the same word form, but the word stress is different, depending on whether you are using them as a noun or a verb. 

Many companies are using artificial intelligence to inCREASE efficiency. (verb) 

You would stress the second syllable of increase if you were reading it aloud. 

The graph shows an INcrease in food expenditure over the past year. (noun) 

You would stress the first syllable of increase if you were reading the sentence aloud.  

Tip: Not sure about word stress? The Cambridge Learner’s Dictionary includes an audio feature so you can click on the different forms of the word and listen to any pronunciation differences.  

Meaning 

Some words look very similar. They might even belong to the same part of speech but have different meanings. Examples include economic and economical, which are both adjectives. 

Tourism is an important part of our country’s economic growth.  

Meaning: Economic = relating to an economy e.g. the way money, trade or industry is organised (adjective).  

It’s more economical to cook at home than to eat out.  

Meaning: Economical = not using a lot of money or resources (adjective). 

Tip: Take care when translating words from your first language. Double-check the meaning of new words in an English dictionary.  

Irregular forms 

Take care when changing adjectives to adverbs as some words follow an irregular pattern and look quite different from each other. 

Adjective: That was a good game.  

Adverb: ✓ They played well.  

              × They played goodly. 

Tip: When you learn a new word, use a dictionary to check what other forms it can take. 

So, what can you do to improve your word formation skills? 

• Parts of Speech: Learn more about the different parts of speech in English. Become familiar with where words go and what they do in a sentence. This will help build your confidence when choosing the right word form.  

• Suffixes: Learn common word endings. Suffixes can give you clues about a word’s form and help you improve your word-building skills.  

 Here are some common suffixes to get you started: 

Test your knowledge of word forms. Choose the correct form of the missing word for each sentence. You can find the answers at the end of the quiz.  

Q1: I want to buy a car that is safe and _________. 

a. economise 

b. economical 

c. economically 

d. economist 

Q2: After ___________ consideration, Samira decided to accept the job in Toronto. 

a. care 

b. caring    

c. careful 

d. carefully 

Q3: The temperature varies __________ across Australia. 

a. consider 

b. considerately 

c. considerable 

d. considerably 

Q4: Can you please __________ the sleeves of this shirt for me? 

a. short 

b. shortly 

c. shorten 

d. shortening 

Q5: Damian shares his mother’s ______in life-long learning.  

a. believe 

b. belief 

c. believable  

d. believably 

 Q6: The concert started ___________ because there was a problem with the sound system.  

a. late 

b. lately 

c. latest

d. latter 

 Q7: Amir studied _______ and graduated earlier than expected.  

a. harden 

b. hard 

c. hardly 

d. hard up 

Q8: Children at our school __________from a range of extracurricular activities.   

a. benefit 

b. beneficial 

c. beneficially 

d. beneficiary 

Q9: The lawyer used expert witnesses to _______ his argument in court. 

a. validate 

b. invalid 

c. valid 

d. validation  

Q10: Sara had to ________ her late assignment with a medical certificate.  

a. justification 

b. justify 

c. justifiable  

d. justifiably 

• Q1: b 

• Q2: c 

• Q3: d 

• Q4: c 

• Q5: b 

• Q6: a 

• Q7: b 

• Q8: a 

• Q9: a 

• Q10: b 

Whether you’re writing an essay, discussing a topic, or filling in a missing word, learning how to use word forms effectively can help you perform your best in the IELTS test.  

For more IELTS test tips, see our other articles on vocabulary for IELTS: 

Use Mind Maps to Build Your Vocabulary Resource for IELTS

How to Improve Your Spelling in the IELTS test

IELTS Listening Test: Tips to Build Key Vocabulary

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