Y05W01VC Word Roots — un- (not / opposite)

The prefix un- comes from Old English and carries the core meaning of 'not' or 'the opposite of'. It is one of the most productive prefixes in English, attaching to adjectives and some verbs to reverse their meaning. Words built with un- appear across everyday and academic writing. This module explores six academic words alongside three further examples in the Word Families section.

Word Families

These three words all use un-. As you read, notice how the meaning 'not / opposite' helps explain each word.

unfair

/ʌnˈfɛː/

un‑fair

adjective

Something that is unfair is not right or equal — it treats people in a way that is unjust or unreasonable.

Example: The students thought it was unfair that some groups had more time than others to complete their project.

Synonyms: unjust, unreasonable, one-sided

Collocations: unfair treatment, unfair advantage, seem unfair

unusual

/ʌnˈjuːʒuəl/

un‑u‑su‑al

adjective

Something that is unusual is different from what is normal or expected — it does not happen very often or is rarely seen.

Example: The teacher asked students for an unusual example that no one else in the class would think of.

Synonyms: uncommon, different, rare

Collocations: unusual for, highly unusual, an unusual situation

uncertain

/ʌnˈsɜːtən/

un‑cer‑tain

adjective

If you are uncertain about something, you are not sure — you do not have a clear or definite answer.

Example: She was uncertain which word to use, so she looked back at the vocabulary list for help.

Synonyms: unsure, unclear, doubtful

Collocations: uncertain about, feel uncertain, remain uncertain

Academic Vocab

describe

/dɪˈskraɪb/

de‑scribe

verb | [describe – described – described]

To describe something is to explain what it looks, sounds, or feels like using words, giving enough detail for someone to picture or understand it.

Word family: description (n.), descriptive (adj.)

Example: She was asked to describe the structure of the rainforest in her science report.

Synonyms: explain, depict, outline

Collocations: describe in detail, describe a scene, describe the process

purpose

/ˈpɜːpəs/

pur‑pose

noun

The purpose of something is the reason it exists or the goal it is meant to achieve.

Word family: purposeful (adj.), purposefully (adv.)

Example: The purpose of the introduction is to give the reader a clear idea of what the text will be about.

Synonyms: aim, goal, reason

Collocations: the purpose of, serve a purpose, main purpose

structure

/ˈstrʏktʃə/

struc‑ture

noun

The structure of something is the way it is organised or arranged, with different parts that connect to form a whole.

Word Breakdown: -ture (suffix meaning ‘the result of a process or action’)

Word family: structural (adj.), structurally (adv.)

Example: The teacher explained the structure of a persuasive text before students began their drafts.

Synonyms: organisation, arrangement, framework

Collocations: text structure, sentence structure, overall structure

feature

/ˈfiːtʃə/

fea‑ture

noun

A feature is a noticeable or important part of something that helps describe or define it.

Word family: featured (adj.), features (n., plural)

Example: One key feature of an information report is the use of subheadings to organise content clearly.

Synonyms: characteristic, quality, element

Collocations: key feature, main feature, a feature of

important

/ɪmˈpɔːtənt/

im‑por‑tant

adjective

Something that is important has great value, meaning or effect, and deserves serious attention.

Word Breakdown: -ant (suffix meaning ‘having a particular quality’)

Word family: importance (n.), importantly (adv.)

Example: It is important to use evidence when explaining your opinion in a persuasive text.

Synonyms: significant, essential, key

Collocations: most important, important to remember, an important role

however

/haʊˈɛvə/

how‑ev‑er

adverb

‘However’ is used to introduce a contrast or a point that is different from or opposite to what was just said.

Example: The report included many facts; however, it did not clearly state the main idea.

Synonyms: but, yet, on the other hand

Collocations: however, this does not mean; however, there are; however, it is important to

Confusing Words

their vs there vs they're

These three words sound exactly the same, which makes them easy to mix up when writing.

  • their — Their' is a possessive pronoun, used to show that something belongs to a group of people — for example, The students handed in their assignments on time.
  • there — There' is used to refer to a place or to introduce the existence of something — for example, Put your books over there or There are five questions to answer.
  • they're — They're' is a contraction of 'they are', so it can always be replaced with those two words — for example, They're working on their projects over there.

Memory rule: Test each word before you use it: if 'they are' fits, use 'they’re'; if it points to a place or existence, use 'there'; and if something belongs to people, use 'their'.