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Understanding similar words

Explore our list of commonly confused words to ensure you're saying what you mean in your work

You'll  discover new terms and improve your vocabulary throughout university – and you can get started with the terms below. 

Commonly confused words

This alphabetical list shows words which are often mixed up. We highlight a word, its meaning and an example of how to use it.

Many of these words have alternative meanings and uses so we've explained the most common meanings here.

Key words

Adverse and averse 

  • Adverse (adj.) — having a negative or harmful effect

Adverse publicity damages the firm's reputation

  • Averse (adj.) — strongly disliking or opposed to

I am not averse to an occasional beer!


Affect and effect

  • Affect (verb) — to have an influence on something

New legislation will affect company reporting procedures. (Company reporting procedures will be affected.)

  • Effect (noun) — result or outcome (of an influence)

The effect of these new requirements will be dramatic. 

So an 'effect' is a noun (a thing), as in the 'Greenhouse Effect'. If you want to say someone is influencing something, you need the verb ('doing word') 'affect'. 


Alternate and alternative

  • Alternate (adj.) — every other

A part is held on alternate Fridays. 

  • Alternative (adj.) — available as another possibility

An alternative solution would be to extend the scope of the report. 

In British use, 'alternate' cannot be use to mean 'alternative', so you should not write 'An alternate solution would be...'


Altogether and all together

  • Altogether (adv.) — in total; completely 

Altogether, the cases cost the company £5 million. 

  • All together — all in one place or all at once

The arrived at court all together. 

'All together' is, perhaps, unlikely to be used in formal writing; you might also avoid 'altogether' by using a phrase such as 'in total'.


Appraise and apprise

  • Appraise (verb) — to assess the value of quality of something 

Candidates will be asked to appraise their own interview performance. 

  • Apprise (verb) — to inform 

The Chancellor was appraised of the crisis. 

Censure and censor

  • Censure (verb) — to express severe disapproval of something 

The CEO was censured for approving misinforming publicity. 

  • Censor (verb) — to find and suppress unacceptable parts of something

The findings of the investigation were censored by the board. 


Complement and compliment

  • complement (verb) — to add to in a way that improves

The new products complement the existing range.

  • compliment (verb) — to express admiration

The team was complimented on its work.

The adjectival forms of these words (‘complementary’ and ‘complimentary’) are often confused. Two surveys might be complementary (they ‘work together’); some feedback might be complimentary (praising). NB: ‘complimentary’ also means ‘free’.


Comprise and compose

  • comprise (verb) — to consist of

The report comprises five sections.

  • compose — (‘be composed of’) (verb) to consist of

The report is composed of five sections.

‘That’s odd’, you should be thinking’, ‘these seem to have the same meaning’. The point is that, strictly speaking, ‘comprise’ must be used actively – you should not write ‘…is comprised of…’.


Continual and continuous

  • continual (adj.) — happening frequently

The department has been damaged by continual scandals.

  • continuous (adj.) — without interruption

A continuous white line means ‘no overtaking’.

These are close in meaning. The most common error is to use ‘continuous’ when the writer doesn’t actually mean ‘without any breaks’ (for example, ‘we have received continuous complaints’).


Criterion and criteria 

  • criterion (noun) — standard (standards) used to judge

The key criterion here is customer satisfaction.

  • criteria (noun) 

Three criteria are used in this evaluation.

‘Criteria’ is just the plural form of ‘criterion’. A really common error is to use ‘criteria’ when the writer actually means just one ‘criterion’.


Discrete and discreet

  • discrete (adj.) — separate or distinct

The department has a discrete identity.

  • discreet (adj.) — careful (not attracting attention)

The journalist made discreet enquiries about the leak.


Draft and draught

  • draft (noun) — preliminary version

The draft plan was submitted to the meeting.

  • draught (noun) — current of cold air

A nasty draught was coming through the door.

In US usage, ‘draft’ is the spelling for both these meanings, but not in British usage. (You’re not very likely to use ‘draught’ in formal writing anyway!)

Elicit and illicit

  • elicit (verb) — to draw out (a response)

The aim of Q.5 was to elicit information about environmental standards.

  • illicit (adj.) forbidden or strongly disapproved of

They were conducting an illicit love affair.


Flaunt and flout

  • flaunt (verb) — display ostentatiously

He is really flaunting his wealth.

  • flout (verb) — openly disregard (a rule or convention)

The branch clearly flouted the regulations.

This is one of those cases where your whole meaning could be lost: consider ‘rules were flaunted’ and ‘rules were flouted’.


Flounder and founder

  • flounder (verb) — to struggle

His departure left the company floundering.

  • founder (verb) — to fail

Inadequate consideration was given to usability, and thus the new guidelines foundered.


Illegal and unlawful

  • illegal (adj.) — against the law

It is now illegal to smoke in most enclosed spaces.

  • unlawful (adj.) — against the rules (in a particular context)

Unfortunately, Mr. Bond, that is an unlawful move in the game of chess.

In football, a handball is unlawful but not illegal.


Imply and infer

  • imply (verb) — indicate by hinting

The conclusion implies that politics affects this issue.

  • infer (verb) — work out through reasoning

By listening again to the speech it was possible to infer that job losses were being considered.

Most commonly, writers use ‘infer’ when they mean ‘imply’; you can avoid this by thinking of ‘infer’ as meaning something like ‘work out’.


Impractical and impracticable

  • impractical (adj.) — not useful or sensible

The variety of languages spoken makes interviewing impractical.

  • impracticable (adj.) — impossible to carry out

The near-impossibility of enforcement makes such tax changes impracticable.


Its and it's 

  • its — belonging to it

The company actively markets its ethical standards.

  • it’s — it is

It’s difficult to assess performance using only this one criterion.

These are so often confused. The question to ask yourself is “do I mean ‘it is’?” If so, don’t be lazy, and write ‘it is’! Only use ‘its’ – without the apostrophe – when you mean ‘belonging to it’. 

Judicious and judicial

  • judicious (adj.) — using good judgement

Taxpayers’ money should be used judiciously.

  • judicial (adj.) — involving a court of law

A judicial enquiry was carried out.


Less and fewer

  • less — not as much

There would be less strife in the world if artists were in charge

  • fewer — not as many

There were fewer problems with the second task.

These two are even more frequently confused. Most commonly, people say or write ‘less’ when they should say ‘fewer’. You must use ‘fewer’ with nouns in their plural form, like ‘problems’ and ‘people’. Use ‘less’ with nouns in their uncountable form.


Loath and loathe 

  • loath (adj.) — reluctant

The auditors were loath to disclose their findings.

  • loathe (verb) — to hate

I loathe Marmite!


Mitigate and militate 

  • mitigate (verb) — to make less severe

This step has helped to mitigate inaccurate reporting.

  • militate (against) (verb) — to be a powerful factor in preventing

The current tax system militates against the proper redistribution of wealth.

Perpetrate and perpetuate

  • perpetrate (verb) — to carry out (a harmful action)

About 50% of violent crimes are perpetrated by people who have been drinking alcohol.

  • perpetuate (verb) — to cause something to continue

These stories perpetuated the myth.


Practice and practise

  • practice (noun) — action (rather than ideas) or training

In practice, this process is more complex.Cricket practice will be held on alternate Sundays.

  • practise (verb) — to rehearse or train

She practised her presentation several times.

‘Practice’ is a noun (a thing); ‘practise’ is a verb (something you do). Thus ‘Tom went to tennis practice to practise his backhand’. Some people remember this by remembering that ‘ice’ is a noun (a thing).


Precede and proceed

  • precede (verb) — to come before

Gordon Brown preceded Alistair Darling as Chancellor of the Exchequer.

  • proceed (verb) — to continue as planned

The lawyers decided not to proceed with the case.


Prescribe and proscribe

  • prescribe (verb) — recommend with authority

Grammatical rules prescribe the way in which words can be used together.

  • proscribe (verb) — to forbid

The athlete was banned for using proscribed drugs.


Prevaricate and procrastinate

  • prevaricate (verb) — to act or speak in an evasive way

When questioned about the actual sum involved, the Minister prevaricated.

  • procrastinate (verb) — to put off doing something

The IMF is likely to procrastinate until it is too late.


Principal and principle

  • principal (adj.) — main

The principal aim of the legislation is to make the process more transparent.

  • principle (noun) — fundamental belief or quality

One principle of the current tax system is that a degree of redistribution is morally right.

Unfortunately, ‘principal’ can also be a noun (meaning ‘college leader’); fortunately, it’s uncommon, but you could write ‘the principal’s principal principle’!


Stationary and stationery

  • stationary (adj.) — not moving

House prices are stationary at the moment.

  • stationery (noun) — writing materials

Stationery costs have dropped this year.

Some people remember the difference by thinking that the ‘e’ in stationery stands for ‘envelope’.


Subsequently and consequently

  • subsequently (adv.) — after (the previous event)

An environmental audit was carried out. Subsequently, such audits became standard practice.

  • consequently (adv.) — as a result of (the previous event)

Writing is the student’s main tool. Consequently, accuracy in writing is essential for good marks.

Occasionally, writers use ‘consequently’ when they don’t actually mean that the second thing happened as a result of the first.


Waive and wave

  • waive (verb) — to refrain from demanding (when the demand would be OK)

In a gesture of goodwill, the hotel waived our parking fee.

  • wave (verb) — to move from side to side

The workers wave as the leader passes.

Download our commonly confused words revision sheet

Download this page as a PDF for your revision notes.


Improving your vocabulary

The most important thing to do in academic writing is to write clearly without confusing or muddling ideas. You shouldn't try to make your writing look more academic by using ‘clever’ words for their own sake – but it's good practice to use a variety of general vocabulary in academic writing. We've listed a range of words to express ideas in assignments below.

These groups of words have similar meanings but they aren't necessarily interchangeable – you should always check their definition before you use them.

Growing your vocabulary


  • certain
  • clear
  • obvious
  • undeniable 
Sentence examples
  • It is clear that…
  • The obvious conclusion is…
  • The idea that…is undeniable.


  • certainly
  • definitely
  • unquestionably
  • clearly
  • patently
  • incontrovertibly
  • obviously
  • undoubtedly
  • undeniably
  • unequivocally
Sentence examples
  • It is definitely not the case that…
  • These anomalies are undoubtedly due to…
  • Smith states unequivocally that…
  • Whilst it is incontrovertibly false to say that…

Note: although the adjective sure can mean ‘completely certain’ the adverb surely is usually used (in academic writing) when you mean ‘I believe…’ or ‘Everybody knows…’ For example: 'It is surely true to say that…' means something like ‘I really do think it is true that…’


  • possible
  • doubtful
  • (im)probable
  • conceivable
  • (im)plausible
  • uncertain
  • (un)likely
  • debatable
Sentence examples
  • One possible reason is (x).
  • Whether (y) is... is debatable. 
  • Though plausible, this theory is...
  • If it quite conceivable that... 


  • possibly
  • arguably
  • probably
  • maybe
  • plausibly
  • perhaps
  • conceivably
  • doubtfully
Sentence examples
  • It is probably true to say that…
  • It is arguably the case that…
  • These are, perhaps, valid points…

Remember that the modal verbs can and may are also widely used to express doubt, especially in their ‘past simple’ forms could and might. For example: 

  • It could be the case that…
  • This might be true in some circumstances.


  • demonstrate
  • reveal
  • show
  • suggest
  • indicate
  • imply
  • prove
  • signify
Sentence examples
  • Figure 1 shows that… …as indicated in Table 3.1.
  • These findings prove that… As these results reveal, …

Take care using the verb prove! You must be sure that the evidence you are using really does prove (make absolutely certain) what you are claiming. It is often safer to use ‘softer’ terms such as show and especially suggest.

Phrases examples
  • According to Figure 5, there are…
  • As can be seen from Table 1.7, it is…
  • It can be seen from Plate 3 that… From this it can be inferred that… (Infer is usually used in the passive form)

Two further phrases that are often seen in writing are ‘Figure 5 tells us that…‘ and ‘We can see from Figure 5 that…‘ Although these phrases are sometimes seen in academic writing, it is best to avoid using the ‘first person’ (us, we) if you can.


  • first
  • principal
  • initial
  • chief
  • primary
  • key
  • main
  • prime
Sentence examples
  • The primary issue is the…
  • The principal application of this theory is to… …
  • is the chief idea challenged here. Of prime importance in this field is…


  • firstly
  • principally
  • initiall
  • cheifly
  • primarily
  • mainly 
Sentence examples
  • This essay looks firstly at…
  • Researchers initially focused on…
  • Practitioners are principally concerned with…



  • secondly
  • besides
  • additionally (in addition)
  • subsequently
  • furthermore
  • next
Sentence examples
  • In addition, it is important to…
  • Furthermore, the process must…
  • Besides this problem is the issue of…
  • Researchers subsequently turned to…

Determiner: another e.g. Another key point is that…


  • lastly
  • ultimately
  • finally
  • overall
  • altogether
Sentence examples
  • Finally, this report examines…
  • There are, overall, three key issues that…
  • Altogether, the problem is not…
  • Ultimately, it might be said that…
  • In conclusion, it could be said that…
  • In summary, the three…
  • There are, therefore…
  • On the whole, then, there are…