I could carpool you could carpool he could carpool we could carpool you could carpool they could carpool
V-ing form
I could be carpooling you could be carpooling he could be carpooling we could be carpooling you could be carpooling they could be carpooling
Perfect
I could have carpooled you could have carpooled he could have carpooled we could have carpooled you could have carpooled they could have carpooled
V-ing perfect
I could have been carpooling you could have been carpooling he could have been carpooling we could have been carpooling you could have been carpooling they could have been carpooling
Negation
Simple form
I could not carpool you could not carpool he could not carpool we could not carpool you could not carpool they could not carpool
V-ing form
I could not be carpooling you could not be carpooling he could not be carpooling we could not be carpooling you could not be carpooling they could not be carpooling
Perfect
I could not have carpooled you could not have carpooled he could not have carpooled we could not have carpooled you could not have carpooled they could not have carpooled
V-ing perfect
I could not have been carpooling you could not have been carpooling he could not have been carpooling we could not have been carpooling you could not have been carpooling they could not have been carpooling
Interrogative form
Simple form
could I carpool? could you carpool? could he carpool? could we carpool? could you carpool? could they carpool?
V-ing form
could I be carpooling? could you be carpooling? could he be carpooling? could we be carpooling? could you be carpooling? could they be carpooling?
Perfect
could I have carpooled? could you have carpooled? could he have carpooled? could we have carpooled? could you have carpooled? could they have carpooled?
V-ing perfect
could I have been carpooling? could you have been carpooling? could he have been carpooling? could we have been carpooling? could you have been carpooling? could they have been carpooling?
Interro-negative form
Simple form
could I not carpool? could you not carpool? could he not carpool? could we not carpool? could you not carpool? could they not carpool?
V-ing form
could I not be carpooling? could you not be carpooling? could he not be carpooling? could we not be carpooling? could you not be carpooling? could they not be carpooling?
Perfect
could I not have carpooled? could you not have carpooled? could he not have carpooled? could we not have carpooled? could you not have carpooled? could they not have carpooled?
V-ing perfect
could I not have been carpooling? could you not have been carpooling? could he not have been carpooling? could we not have been carpooling? could you not have been carpooling? could they not have been carpooling?