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