grammar

What is it called when you use a negative to imply a positive for example 'works well doesn't it'. I know this is technically bad grammar but is there a specific term for this phrase?

The 'doesn't it' bit is sometimes called a 'question tag'.

[Casiopea]

Originally Posted by Unregistered

What is it called when you use a negative to imply a positive for example 'works well doesn't it'. I know this is technically bad grammar but is there a specific term for this phrase?

I agree with TMB, question tag is the term you're looking for. Please note, there's a comma before the tag,

EX: It works well, doesn't it?

Other examples
She will go, won't she?
They are nice, aren't they?
It is going to rain, isn't it?
We should go, shouldn't we?
I can drive, can't I?

Note, when the main verb is HAVE/HAS, either haven't/hasn't or don't/doesn't is used.

EX: She has a car, hasn't she? / doesn't she?
EX: They have a car, haven't they? / don't they?