I could bicycle you could bicycle she could bicycle we could bicycle you could bicycle they could bicycle
V-ing form
I could be bicycling you could be bicycling she could be bicycling we could be bicycling you could be bicycling they could be bicycling
Perfect
I could have bicycled you could have bicycled she could have bicycled we could have bicycled you could have bicycled they could have bicycled
V-ing perfect
I could have been bicycling you could have been bicycling she could have been bicycling we could have been bicycling you could have been bicycling they could have been bicycling
Negation
Simple form
I couldn't bicycle you couldn't bicycle she couldn't bicycle we couldn't bicycle you couldn't bicycle they couldn't bicycle
V-ing form
I couldn't be bicycling you couldn't be bicycling she couldn't be bicycling we couldn't be bicycling you couldn't be bicycling they couldn't be bicycling
Perfect
I couldn't have bicycled you couldn't have bicycled she couldn't have bicycled we couldn't have bicycled you couldn't have bicycled they couldn't have bicycled
V-ing perfect
I couldn't have been bicycling you couldn't have been bicycling she couldn't have been bicycling we couldn't have been bicycling you couldn't have been bicycling they couldn't have been bicycling
Interrogative form
Simple form
could I bicycle? could you bicycle? could she bicycle? could we bicycle? could you bicycle? could they bicycle?
V-ing form
could I be bicycling? could you be bicycling? could she be bicycling? could we be bicycling? could you be bicycling? could they be bicycling?
Perfect
could I have bicycled? could you have bicycled? could she have bicycled? could we have bicycled? could you have bicycled? could they have bicycled?
V-ing perfect
could I have been bicycling? could you have been bicycling? could she have been bicycling? could we have been bicycling? could you have been bicycling? could they have been bicycling?
Interro-negative form
Simple form
couldn't I bicycle? couldn't you bicycle? couldn't she bicycle? couldn't we bicycle? couldn't you bicycle? couldn't they bicycle?
V-ing form
couldn't I be bicycling? couldn't you be bicycling? couldn't she be bicycling? couldn't we be bicycling? couldn't you be bicycling? couldn't they be bicycling?
Perfect
couldn't I have bicycled? couldn't you have bicycled? couldn't she have bicycled? couldn't we have bicycled? couldn't you have bicycled? couldn't they have bicycled?
V-ing perfect
couldn't I have been bicycling? couldn't you have been bicycling? couldn't she have been bicycling? couldn't we have been bicycling? couldn't you have been bicycling? couldn't they have been bicycling?