I could enlarge you could enlarge he could enlarge we could enlarge you could enlarge they could enlarge
V-ing form
I could be enlarging you could be enlarging he could be enlarging we could be enlarging you could be enlarging they could be enlarging
Perfect
I could have enlarged you could have enlarged he 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 he 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 he 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 he 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 he 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 he 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 he enlarge? could we enlarge? could you enlarge? could they enlarge?
V-ing form
could I be enlarging? could you be enlarging? could he be enlarging? could we be enlarging? could you be enlarging? could they be enlarging?
Perfect
could I have enlarged? could you have enlarged? could he 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 he 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 he 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 he 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 he 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 he have been enlarging? couldn't we have been enlarging? couldn't you have been enlarging? couldn't they have been enlarging?