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