I could recycle you could recycle she could recycle we could recycle you could recycle they could recycle
V-ing form
I could be recycling you could be recycling she could be recycling we could be recycling you could be recycling they could be recycling
Perfect
I could have recycled you could have recycled she could have recycled we could have recycled you could have recycled they could have recycled
V-ing perfect
I could have been recycling you could have been recycling she could have been recycling we could have been recycling you could have been recycling they could have been recycling
Negation
Simple form
I could not recycle you could not recycle she could not recycle we could not recycle you could not recycle they could not recycle
V-ing form
I could not be recycling you could not be recycling she could not be recycling we could not be recycling you could not be recycling they could not be recycling
Perfect
I could not have recycled you could not have recycled she could not have recycled we could not have recycled you could not have recycled they could not have recycled
V-ing perfect
I could not have been recycling you could not have been recycling she could not have been recycling we could not have been recycling you could not have been recycling they could not have been recycling
Interrogative form
Simple form
could I recycle? could you recycle? could she recycle? could we recycle? could you recycle? could they recycle?
V-ing form
could I be recycling? could you be recycling? could she be recycling? could we be recycling? could you be recycling? could they be recycling?
Perfect
could I have recycled? could you have recycled? could she have recycled? could we have recycled? could you have recycled? could they have recycled?
V-ing perfect
could I have been recycling? could you have been recycling? could she have been recycling? could we have been recycling? could you have been recycling? could they have been recycling?
Interro-negative form
Simple form
could I not recycle? could you not recycle? could she not recycle? could we not recycle? could you not recycle? could they not recycle?
V-ing form
could I not be recycling? could you not be recycling? could she not be recycling? could we not be recycling? could you not be recycling? could they not be recycling?
Perfect
could I not have recycled? could you not have recycled? could she not have recycled? could we not have recycled? could you not have recycled? could they not have recycled?
V-ing perfect
could I not have been recycling? could you not have been recycling? could she not have been recycling? could we not have been recycling? could you not have been recycling? could they not have been recycling?