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