We can useprettyas an adverb, before an adjective or another adverb, meaning ‘quite, but not extremely’. It is informal:
I’mpretty surewe’ve met before. Were you at Clare Harding’s wedding?
You need to get therepretty earlyto get a good seat.
Pretty wellas a modifier means ‘almost’:
That’spretty wellall we need to do this morning, so why don’t we break for lunch?
We don’t useprettyin more formal situations. We usequiteorfairly:
[in a job application letter]
At present I am employed at a branch of the National Bank in afairly largecity.
Not: …in a pretty large city.
Prettydoes not mean the same asvery:
It wasverykind of you to lend us your car when we stayed with you.
Not:It was pretty kind of you…
We don’t useprettyin negative sentences:
The restaurant wasn’tverygood, really. I don’t think we’ll go there again.(orThe restaurant wasn’tsogood …)
Not: …wasn’t pretty good…