I could unravel you could unravel she could unravel we could unravel you could unravel they could unravel
V-ing form
I could be unravelling you could be unravelling she could be unravelling we could be unravelling you could be unravelling they could be unravelling
Perfect
I could have unravelled you could have unravelled she could have unravelled we could have unravelled you could have unravelled they could have unravelled
V-ing perfect
I could have been unravelling you could have been unravelling she could have been unravelling we could have been unravelling you could have been unravelling they could have been unravelling
Negation
Simple form
I couldn't unravel you couldn't unravel she couldn't unravel we couldn't unravel you couldn't unravel they couldn't unravel
V-ing form
I couldn't be unravelling you couldn't be unravelling she couldn't be unravelling we couldn't be unravelling you couldn't be unravelling they couldn't be unravelling
Perfect
I couldn't have unravelled you couldn't have unravelled she couldn't have unravelled we couldn't have unravelled you couldn't have unravelled they couldn't have unravelled
V-ing perfect
I couldn't have been unravelling you couldn't have been unravelling she couldn't have been unravelling we couldn't have been unravelling you couldn't have been unravelling they couldn't have been unravelling
Interrogative form
Simple form
could I unravel? could you unravel? could she unravel? could we unravel? could you unravel? could they unravel?
V-ing form
could I be unravelling? could you be unravelling? could she be unravelling? could we be unravelling? could you be unravelling? could they be unravelling?
Perfect
could I have unravelled? could you have unravelled? could she have unravelled? could we have unravelled? could you have unravelled? could they have unravelled?
V-ing perfect
could I have been unravelling? could you have been unravelling? could she have been unravelling? could we have been unravelling? could you have been unravelling? could they have been unravelling?
Interro-negative form
Simple form
couldn't I unravel? couldn't you unravel? couldn't she unravel? couldn't we unravel? couldn't you unravel? couldn't they unravel?
V-ing form
couldn't I be unravelling? couldn't you be unravelling? couldn't she be unravelling? couldn't we be unravelling? couldn't you be unravelling? couldn't they be unravelling?
Perfect
couldn't I have unravelled? couldn't you have unravelled? couldn't she have unravelled? couldn't we have unravelled? couldn't you have unravelled? couldn't they have unravelled?
V-ing perfect
couldn't I have been unravelling? couldn't you have been unravelling? couldn't she have been unravelling? couldn't we have been unravelling? couldn't you have been unravelling? couldn't they have been unravelling?