What's the difference between 'fast' and 'quickly'?

Blog reader Paul asks:

I’ve seen ‘fast’ and ‘quickly’ used as though they were interchangeable. Is this correct?

Strictly speaking, fast is an adjective while quickly is an adverb. Fast refers to speed, and  quickly refers  to time.

For example:

‘That car is very fast.’

‘The car quickly pulled over.’

The confusion arises because American English speakers have no qualms about using fast as an adverb. British English speakers, however, tend to avoid that usage.

The definitive guide to transforming the writing of individuals and teams

GET YOUR FREE PDF COPY NOW

Comments