IELTS Synonyms: Better Words for Increase, Good, People

Search data is unusually clear about which words IELTS candidates want to replace. Increase, good, people, children, important, problem, big and say come up again and again — the same handful of ordinary words that every essay leans on.

The lists that answer those searches usually give you ten alternatives in a row, as if they were interchangeable. They are not. Increase, soar and creep up all describe something going up, and using the wrong one is a clearer error than using increase three times would have been.

So this list is sorted by strength and context, and every group ends with the one to be careful about.

increase / decrease

The most-requested group, and the one where strength matters most.

Going up	Strength	Use it for
edge up / creep up	slight	Small, slow movement
rise	neutral	Almost anything
grow	neutral	Quantities, economies, populations
climb	moderate	Steady upward movement over time
surge	strong	Sudden, large
soar	strong	Dramatic, usually welcome or striking
rocket / skyrocket	very strong	⚠️ Informal — fine in Speaking, risky in Task 2

Going down	Strength	Use it for
dip	slight	A small, often temporary fall
fall / drop	neutral	Almost anything
decline	neutral, formal	Trends over time
decrease	neutral, formal	Measured quantities
plummet	very strong	A steep collapse
plunge	very strong	Same, slightly more dramatic

Careful: soar and plummet are Task 1 words for genuinely dramatic movement. Using them for a 3% change is the single most common Task 1 vocabulary error. And all of these are verbs — the noun forms differ: a rise in, an increase in, a decline in, but never a soar in.

good / bad

Both words are too vague for Task 2 on their own, but the replacements are not general-purpose.

Instead of good	Use it for
beneficial	Effects on health, society, learning — needs to or for
positive	Effects, attitudes, outcomes
valuable	Things worth having: experience, skills, resources
effective	Methods and policies that work
favourable	Conditions, terms, comparisons
desirable	Outcomes people want

Instead of bad	Use it for
detrimental	Harm to health or development — needs to
harmful	Direct physical or mental damage
negative	Effects, impacts, attitudes
adverse	Formal; effects, conditions, weather
damaging	Reputations, relationships, environments
counterproductive	Actions that defeat their own purpose

Careful: beneficial and detrimental both need a preposition. A detrimental policy is odd; a policy detrimental to public health is right.

people

Use	When
individuals	Emphasising people separately rather than as a group
the public	People collectively, in relation to authorities
citizens	In the context of a state, rights, or duties
the population	Demographic or statistical contexts
society	The collective structure, not the members
members of the public	Formal; often in policy contexts

Careful: society is not a synonym for people. Society thinks is wrong — society does not think. Also, people is already plural: peoples means ethnic or national groups, which is almost never what you mean.

children

Use	When
young people	Broad, includes teenagers — safest general choice
youngsters	Slightly informal, fine in Speaking
the young	Formal and collective: the young are more adaptable
minors	Legal contexts only
pupils / students	When the school context is the point
offspring	⚠️ Biological or animal contexts — avoid for humans

Careful: child and children are perfectly good words. You are not required to replace them, and offspring in an education essay reads badly.

important

Use	Strength
significant	Neutral; means measurable or noteworthy
key	Neutral, slightly informal
essential	Strong: cannot do without
crucial	Strong: decisive
vital	Strong: life-or-death connotation
paramount	Very strong, very formal — one per essay at most

Careful: significant has a statistical sense. A significant increase suggests measurable size, not just importance — useful in Task 1, potentially misleading elsewhere.

problem

Use	When
issue	Milder; something to be discussed or resolved
challenge	Framing it as surmountable
difficulty	Something that impedes progress
drawback	A downside of an otherwise reasonable thing
obstacle	Something blocking a specific goal
crisis	⚠️ Severe and urgent only — heavily overused

Careful: many essays call everything a crisis. If a crisis is not urgent and severe, the word undermines you.

big / small

Instead of big	Use it for
substantial	Amounts and quantities
considerable	Amounts, effort, time
significant	Measurable difference
vast	Scale: areas, differences, majorities
major	Importance: a major factor, a major change

Instead of small	Use it for
minor	Importance, not size
slight	Change or difference
limited	Resources, access, scope
modest	Amounts, growth, income
negligible	So small it can be ignored

Careful: none of these describes physical size. A substantial house means a solidly built one, not a big one — use large.

say / show

Useful for reporting evidence and arguments, where repetition is most visible.

Instead of say	When
argue	Presenting a case
claim	Signals you may not accept it
maintain	Holding a position under challenge
suggest	Tentative
point out	Drawing attention to a fact

Instead of show	When
demonstrate	Evidence proving something
indicate	Evidence pointing towards something
reveal	Something previously hidden
illustrate	Giving an example of a wider point
highlight	Drawing emphasis

Careful: claim is not neutral. Scientists claim that… subtly suggests you doubt them — use argue or have found unless the doubt is intended.

The principle underneath all of this

Eight groups above, and the same warning at the bottom of each: these words are not interchangeable. That is because synonyms differ in strength, in register, and in what they can attach to — and IELTS assesses precision, not variety for its own sake.

Which leads to the rule worth remembering: if you are unsure which alternative fits, use the ordinary word. Increase used correctly costs you nothing. Skyrocket used for a 2% change costs you real marks.

This is the same logic as paraphrasing, where the structural moves matter more than the word swaps, and as linking words, where fewer and better beats more. The topic lists in IELTS vocabulary by topic are built the same way.