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