I could boggle you could boggle she could boggle we could boggle you could boggle they could boggle
V-ing form
I could be boggling you could be boggling she could be boggling we could be boggling you could be boggling they could be boggling
Perfect
I could have boggled you could have boggled she could have boggled we could have boggled you could have boggled they could have boggled
V-ing perfect
I could have been boggling you could have been boggling she could have been boggling we could have been boggling you could have been boggling they could have been boggling
Negation
Simple form
I could not boggle you could not boggle she could not boggle we could not boggle you could not boggle they could not boggle
V-ing form
I could not be boggling you could not be boggling she could not be boggling we could not be boggling you could not be boggling they could not be boggling
Perfect
I could not have boggled you could not have boggled she could not have boggled we could not have boggled you could not have boggled they could not have boggled
V-ing perfect
I could not have been boggling you could not have been boggling she could not have been boggling we could not have been boggling you could not have been boggling they could not have been boggling
Interrogative form
Simple form
could I boggle? could you boggle? could she boggle? could we boggle? could you boggle? could they boggle?
V-ing form
could I be boggling? could you be boggling? could she be boggling? could we be boggling? could you be boggling? could they be boggling?
Perfect
could I have boggled? could you have boggled? could she have boggled? could we have boggled? could you have boggled? could they have boggled?
V-ing perfect
could I have been boggling? could you have been boggling? could she have been boggling? could we have been boggling? could you have been boggling? could they have been boggling?
Interro-negative form
Simple form
could I not boggle? could you not boggle? could she not boggle? could we not boggle? could you not boggle? could they not boggle?
V-ing form
could I not be boggling? could you not be boggling? could she not be boggling? could we not be boggling? could you not be boggling? could they not be boggling?
Perfect
could I not have boggled? could you not have boggled? could she not have boggled? could we not have boggled? could you not have boggled? could they not have boggled?
V-ing perfect
could I not have been boggling? could you not have been boggling? could she not have been boggling? could we not have been boggling? could you not have been boggling? could they not have been boggling?