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