Which sentence is the correct one?

bassaIf you will do this, you will end up regreting it.

This is the correct one.

bassaThnak

I see you are also studying ancient Egyptian.

Thanks

Dont forget the double-t in regretting.

bassa1) If you will do this, you will end up regreting it.

I was taught not to use the first "will," but I suppose it's correct.

I'd use it only if it's meant to show intention -- a sort of polite form.

If you will do this for me, I'll/I'd be very grateful. (If you'd do this for me, I'll/I'd be very grateful.)

If

Talk about reading the question too fast!

bassaIf you will do this, you will end up regreting it.

Almost, but not quite.

If you do this, you will end up regretting it.

Thanks, Philip and Avangi!

CJ

after end up, you should use a verb+ing, so the first one is more acceptable.

but both sentences are incorrect anyway, because your sentence should be first conditional: If you do this(not future tense) , you will end up regretting it