Coincidence vs Small world

When to use each in English, with meaning, register, and examples.

Coincidence

Top 2,000 (common)B2noun

Small world

Top 5,000 (fairly common)
Most common: Coincidence
 CoincidenceSmall world
Pronunciation🇬🇧 /["/kəʊˈɪnsɪdəns/"]/🇺🇸 /["/kəʊˈɪnsɪdəns/"]/🇬🇧 //smɔːl wɜːrld//🇺🇸 //smɔl wɜrld//
MeaningWhen two things happen at the same time by chance.A surprising connection between people in a vast space
ExampleIt was just a coincidence that we ran into each other at the café.I can't believe you know my cousin! It's such a small world.
RegisterNeutralNeutral
How commonTop 2,000 (common)Top 5,000 (fairly common)
CEFR levelB2-
Part of speechnoun
Collocationscomplete, pure, sheer, series, set, string, happen, by (a) coincidencewhat a small world, in a small world, it's a small world
Antonymsintention, design-
Common mistakesConfusing 'coincidence' with 'coincidental' — the latter is an adjective., Using 'coincidence' when describing causal relationships instead of chance., Overusing in formal writing; it's better in casual conversation.Using 'small world' without context or reason can confuse listeners., Confusing 'small world' with 'world is small', which is less common., Overusing the phrase in formal writing.
Usage notesUse 'coincidence' when referring to events that happen together unexpectedly. Avoid using it in formal scientific contexts, where 'correlation' might be more appropriate.Often used to express surprise at coincidental meetings or connections. Common in informal conversation, but can be used in more formal contexts as well.

See it in real clips

Coincidence
Small world

Frequently asked questions: Coincidence vs Small world

What's the difference between Coincidence and Small world?

Coincidence: When two things happen at the same time by chance. Small world: A surprising connection between people in a vast space

Which is more common: Coincidence and Small world?

Coincidence is the most common in everyday English.

Can you show an example of each?

Coincidence: It was just a coincidence that we ran into each other at the café. Small world: I can't believe you know my cousin! It's such a small world.

Can I use Coincidence and Small world interchangeably?

Not always. Coincidence and Small world are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.

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