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