English verb conjugation
COULD TILLER

Regular verb: tiller - tillered - tillered

Affirmation

Simple form	V-ing form
I could tiller you could tiller he could tiller we could tiller you could tiller they could tiller	I could be tillering you could be tillering he could be tillering we could be tillering you could be tillering they could be tillering
Perfect	V-ing perfect
I could have tillered you could have tillered he could have tillered we could have tillered you could have tillered they could have tillered	I could have been tillering you could have been tillering he could have been tillering we could have been tillering you could have been tillering they could have been tillering

Negation

Simple form	V-ing form
I could not tiller you could not tiller he could not tiller we could not tiller you could not tiller they could not tiller	I could not be tillering you could not be tillering he could not be tillering we could not be tillering you could not be tillering they could not be tillering
Perfect	V-ing perfect
I could not have tillered you could not have tillered he could not have tillered we could not have tillered you could not have tillered they could not have tillered	I could not have been tillering you could not have been tillering he could not have been tillering we could not have been tillering you could not have been tillering they could not have been tillering

Interrogative form

Simple form	V-ing form
could I tiller? could you tiller? could he tiller? could we tiller? could you tiller? could they tiller?	could I be tillering? could you be tillering? could he be tillering? could we be tillering? could you be tillering? could they be tillering?
Perfect	V-ing perfect
could I have tillered? could you have tillered? could he have tillered? could we have tillered? could you have tillered? could they have tillered?	could I have been tillering? could you have been tillering? could he have been tillering? could we have been tillering? could you have been tillering? could they have been tillering?

Interro-negative form

Simple form	V-ing form
could I not tiller? could you not tiller? could he not tiller? could we not tiller? could you not tiller? could they not tiller?	could I not be tillering? could you not be tillering? could he not be tillering? could we not be tillering? could you not be tillering? could they not be tillering?
Perfect	V-ing perfect
could I not have tillered? could you not have tillered? could he not have tillered? could we not have tillered? could you not have tillered? could they not have tillered?	could I not have been tillering? could you not have been tillering? could he not have been tillering? could we not have been tillering? could you not have been tillering? could they not have been tillering?