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