I could chatter you could chatter she could chatter we could chatter you could chatter they could chatter
V-ing form
I could be chattering you could be chattering she could be chattering we could be chattering you could be chattering they could be chattering
Perfect
I could have chattered you could have chattered she could have chattered we could have chattered you could have chattered they could have chattered
V-ing perfect
I could have been chattering you could have been chattering she could have been chattering we could have been chattering you could have been chattering they could have been chattering
Negation
Simple form
I could not chatter you could not chatter she could not chatter we could not chatter you could not chatter they could not chatter
V-ing form
I could not be chattering you could not be chattering she could not be chattering we could not be chattering you could not be chattering they could not be chattering
Perfect
I could not have chattered you could not have chattered she could not have chattered we could not have chattered you could not have chattered they could not have chattered
V-ing perfect
I could not have been chattering you could not have been chattering she could not have been chattering we could not have been chattering you could not have been chattering they could not have been chattering
Interrogative form
Simple form
could I chatter? could you chatter? could she chatter? could we chatter? could you chatter? could they chatter?
V-ing form
could I be chattering? could you be chattering? could she be chattering? could we be chattering? could you be chattering? could they be chattering?
Perfect
could I have chattered? could you have chattered? could she have chattered? could we have chattered? could you have chattered? could they have chattered?
V-ing perfect
could I have been chattering? could you have been chattering? could she have been chattering? could we have been chattering? could you have been chattering? could they have been chattering?
Interro-negative form
Simple form
could I not chatter? could you not chatter? could she not chatter? could we not chatter? could you not chatter? could they not chatter?
V-ing form
could I not be chattering? could you not be chattering? could she not be chattering? could we not be chattering? could you not be chattering? could they not be chattering?
Perfect
could I not have chattered? could you not have chattered? could she not have chattered? could we not have chattered? could you not have chattered? could they not have chattered?
V-ing perfect
could I not have been chattering? could you not have been chattering? could she not have been chattering? could we not have been chattering? could you not have been chattering? could they not have been chattering?