I could putter you could putter she could putter we could putter you could putter they could putter
V-ing form
I could be puttering you could be puttering she could be puttering we could be puttering you could be puttering they could be puttering
Perfect
I could have puttered you could have puttered she could have puttered we could have puttered you could have puttered they could have puttered
V-ing perfect
I could have been puttering you could have been puttering she could have been puttering we could have been puttering you could have been puttering they could have been puttering
Negation
Simple form
I could not putter you could not putter she could not putter we could not putter you could not putter they could not putter
V-ing form
I could not be puttering you could not be puttering she could not be puttering we could not be puttering you could not be puttering they could not be puttering
Perfect
I could not have puttered you could not have puttered she could not have puttered we could not have puttered you could not have puttered they could not have puttered
V-ing perfect
I could not have been puttering you could not have been puttering she could not have been puttering we could not have been puttering you could not have been puttering they could not have been puttering
Interrogative form
Simple form
could I putter? could you putter? could she putter? could we putter? could you putter? could they putter?
V-ing form
could I be puttering? could you be puttering? could she be puttering? could we be puttering? could you be puttering? could they be puttering?
Perfect
could I have puttered? could you have puttered? could she have puttered? could we have puttered? could you have puttered? could they have puttered?
V-ing perfect
could I have been puttering? could you have been puttering? could she have been puttering? could we have been puttering? could you have been puttering? could they have been puttering?
Interro-negative form
Simple form
could I not putter? could you not putter? could she not putter? could we not putter? could you not putter? could they not putter?
V-ing form
could I not be puttering? could you not be puttering? could she not be puttering? could we not be puttering? could you not be puttering? could they not be puttering?
Perfect
could I not have puttered? could you not have puttered? could she not have puttered? could we not have puttered? could you not have puttered? could they not have puttered?
V-ing perfect
could I not have been puttering? could you not have been puttering? could she not have been puttering? could we not have been puttering? could you not have been puttering? could they not have been puttering?