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