I could buttonhole you could buttonhole he could buttonhole we could buttonhole you could buttonhole they could buttonhole
V-ing form
I could be buttonholing you could be buttonholing he could be buttonholing we could be buttonholing you could be buttonholing they could be buttonholing
Perfect
I could have buttonholed you could have buttonholed he 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 he could have been buttonholing we could have been buttonholing you could have been buttonholing they could have been buttonholing
Negation
Simple form
I couldn't buttonhole you couldn't buttonhole he couldn't buttonhole we couldn't buttonhole you couldn't buttonhole they couldn't buttonhole
V-ing form
I couldn't be buttonholing you couldn't be buttonholing he couldn't be buttonholing we couldn't be buttonholing you couldn't be buttonholing they couldn't be buttonholing
Perfect
I couldn't have buttonholed you couldn't have buttonholed he couldn't have buttonholed we couldn't have buttonholed you couldn't have buttonholed they couldn't have buttonholed
V-ing perfect
I couldn't have been buttonholing you couldn't have been buttonholing he couldn't have been buttonholing we couldn't have been buttonholing you couldn't have been buttonholing they couldn't have been buttonholing
Interrogative form
Simple form
could I buttonhole? could you buttonhole? could he buttonhole? could we buttonhole? could you buttonhole? could they buttonhole?
V-ing form
could I be buttonholing? could you be buttonholing? could he be buttonholing? could we be buttonholing? could you be buttonholing? could they be buttonholing?
Perfect
could I have buttonholed? could you have buttonholed? could he 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 he have been buttonholing? could we have been buttonholing? could you have been buttonholing? could they have been buttonholing?
Interro-negative form
Simple form
couldn't I buttonhole? couldn't you buttonhole? couldn't he buttonhole? couldn't we buttonhole? couldn't you buttonhole? couldn't they buttonhole?
V-ing form
couldn't I be buttonholing? couldn't you be buttonholing? couldn't he be buttonholing? couldn't we be buttonholing? couldn't you be buttonholing? couldn't they be buttonholing?
Perfect
couldn't I have buttonholed? couldn't you have buttonholed? couldn't he have buttonholed? couldn't we have buttonholed? couldn't you have buttonholed? couldn't they have buttonholed?
V-ing perfect
couldn't I have been buttonholing? couldn't you have been buttonholing? couldn't he have been buttonholing? couldn't we have been buttonholing? couldn't you have been buttonholing? couldn't they have been buttonholing?