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