present simple :
Bill works harder than John.
Does Bill work harder than John?
Bill doesn't work harder than John.
past simple:
Bill worked harder than John.
Did Bill work harder than John?
Bill didn't work harder than John.
present continuous:
Bill is working harder than John.
Is Bill working harder than John?
Bill isn't working harder than John?
past continuous :
Bill was working harder than John.
Was Bill working harder than John?
Bill wasn't working harder than John.
Proszę, wszystko powinno być dobrze.