I could buttonhole you could buttonhole she could buttonhole we could buttonhole you could buttonhole they could buttonhole
V-ing form
I could be buttonholing you could be buttonholing she could be buttonholing we could be buttonholing you could be buttonholing they could be buttonholing
Perfect
I could have buttonholed you could have buttonholed she could have buttonholed we could have buttonholed you could have buttonholed they could have buttonholed
V-ing perfect
I could have been buttonholing you could have been buttonholing she could have been buttonholing we could have been buttonholing you could have been buttonholing they could have been buttonholing
Negation
Simple form
I could not buttonhole you could not buttonhole she could not buttonhole we could not buttonhole you could not buttonhole they could not buttonhole
V-ing form
I could not be buttonholing you could not be buttonholing she could not be buttonholing we could not be buttonholing you could not be buttonholing they could not be buttonholing
Perfect
I could not have buttonholed you could not have buttonholed she could not have buttonholed we could not have buttonholed you could not have buttonholed they could not have buttonholed
V-ing perfect
I could not have been buttonholing you could not have been buttonholing she could not have been buttonholing we could not have been buttonholing you could not have been buttonholing they could not have been buttonholing
Interrogative form
Simple form
could I buttonhole? could you buttonhole? could she buttonhole? could we buttonhole? could you buttonhole? could they buttonhole?
V-ing form
could I be buttonholing? could you be buttonholing? could she be buttonholing? could we be buttonholing? could you be buttonholing? could they be buttonholing?
Perfect
could I have buttonholed? could you have buttonholed? could she have buttonholed? could we have buttonholed? could you have buttonholed? could they have buttonholed?
V-ing perfect
could I have been buttonholing? could you have been buttonholing? could she have been buttonholing? could we have been buttonholing? could you have been buttonholing? could they have been buttonholing?
Interro-negative form
Simple form
could I not buttonhole? could you not buttonhole? could she not buttonhole? could we not buttonhole? could you not buttonhole? could they not buttonhole?
V-ing form
could I not be buttonholing? could you not be buttonholing? could she not be buttonholing? could we not be buttonholing? could you not be buttonholing? could they not be buttonholing?
Perfect
could I not have buttonholed? could you not have buttonholed? could she not have buttonholed? could we not have buttonholed? could you not have buttonholed? could they not have buttonholed?
V-ing perfect
could I not have been buttonholing? could you not have been buttonholing? could she not have been buttonholing? could we not have been buttonholing? could you not have been buttonholing? could they not have been buttonholing?