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