I could befoul you could befoul she could befoul we could befoul you could befoul they could befoul
V-ing form
I could be befouling you could be befouling she could be befouling we could be befouling you could be befouling they could be befouling
Perfect
I could have befouled you could have befouled she could have befouled we could have befouled you could have befouled they could have befouled
V-ing perfect
I could have been befouling you could have been befouling she could have been befouling we could have been befouling you could have been befouling they could have been befouling
Negation
Simple form
I could not befoul you could not befoul she could not befoul we could not befoul you could not befoul they could not befoul
V-ing form
I could not be befouling you could not be befouling she could not be befouling we could not be befouling you could not be befouling they could not be befouling
Perfect
I could not have befouled you could not have befouled she could not have befouled we could not have befouled you could not have befouled they could not have befouled
V-ing perfect
I could not have been befouling you could not have been befouling she could not have been befouling we could not have been befouling you could not have been befouling they could not have been befouling
Interrogative form
Simple form
could I befoul? could you befoul? could she befoul? could we befoul? could you befoul? could they befoul?
V-ing form
could I be befouling? could you be befouling? could she be befouling? could we be befouling? could you be befouling? could they be befouling?
Perfect
could I have befouled? could you have befouled? could she have befouled? could we have befouled? could you have befouled? could they have befouled?
V-ing perfect
could I have been befouling? could you have been befouling? could she have been befouling? could we have been befouling? could you have been befouling? could they have been befouling?
Interro-negative form
Simple form
could I not befoul? could you not befoul? could she not befoul? could we not befoul? could you not befoul? could they not befoul?
V-ing form
could I not be befouling? could you not be befouling? could she not be befouling? could we not be befouling? could you not be befouling? could they not be befouling?
Perfect
could I not have befouled? could you not have befouled? could she not have befouled? could we not have befouled? could you not have befouled? could they not have befouled?
V-ing perfect
could I not have been befouling? could you not have been befouling? could she not have been befouling? could we not have been befouling? could you not have been befouling? could they not have been befouling?