I could babysit you could babysit she could babysit we could babysit you could babysit they could babysit
V-ing form
I could be babysiting you could be babysiting she could be babysiting we could be babysiting you could be babysiting they could be babysiting
Perfect
I could have babysat you could have babysat she could have babysat we could have babysat you could have babysat they could have babysat
V-ing perfect
I could have been babysiting you could have been babysiting she could have been babysiting we could have been babysiting you could have been babysiting they could have been babysiting
Negation
Simple form
I could not babysit you could not babysit she could not babysit we could not babysit you could not babysit they could not babysit
V-ing form
I could not be babysiting you could not be babysiting she could not be babysiting we could not be babysiting you could not be babysiting they could not be babysiting
Perfect
I could not have babysat you could not have babysat she could not have babysat we could not have babysat you could not have babysat they could not have babysat
V-ing perfect
I could not have been babysiting you could not have been babysiting she could not have been babysiting we could not have been babysiting you could not have been babysiting they could not have been babysiting
Interrogative form
Simple form
could I babysit? could you babysit? could she babysit? could we babysit? could you babysit? could they babysit?
V-ing form
could I be babysiting? could you be babysiting? could she be babysiting? could we be babysiting? could you be babysiting? could they be babysiting?
Perfect
could I have babysat? could you have babysat? could she have babysat? could we have babysat? could you have babysat? could they have babysat?
V-ing perfect
could I have been babysiting? could you have been babysiting? could she have been babysiting? could we have been babysiting? could you have been babysiting? could they have been babysiting?
Interro-negative form
Simple form
could I not babysit? could you not babysit? could she not babysit? could we not babysit? could you not babysit? could they not babysit?
V-ing form
could I not be babysiting? could you not be babysiting? could she not be babysiting? could we not be babysiting? could you not be babysiting? could they not be babysiting?
Perfect
could I not have babysat? could you not have babysat? could she not have babysat? could we not have babysat? could you not have babysat? could they not have babysat?
V-ing perfect
could I not have been babysiting? could you not have been babysiting? could she not have been babysiting? could we not have been babysiting? could you not have been babysiting? could they not have been babysiting?