I could impress you could impress he could impress we could impress you could impress they could impress
V-ing form
I could be impressing you could be impressing he could be impressing we could be impressing you could be impressing they could be impressing
Perfect
I could have impressed you could have impressed he could have impressed we could have impressed you could have impressed they could have impressed
V-ing perfect
I could have been impressing you could have been impressing he could have been impressing we could have been impressing you could have been impressing they could have been impressing
Negation
Simple form
I couldn't impress you couldn't impress he couldn't impress we couldn't impress you couldn't impress they couldn't impress
V-ing form
I couldn't be impressing you couldn't be impressing he couldn't be impressing we couldn't be impressing you couldn't be impressing they couldn't be impressing
Perfect
I couldn't have impressed you couldn't have impressed he couldn't have impressed we couldn't have impressed you couldn't have impressed they couldn't have impressed
V-ing perfect
I couldn't have been impressing you couldn't have been impressing he couldn't have been impressing we couldn't have been impressing you couldn't have been impressing they couldn't have been impressing
Interrogative form
Simple form
could I impress? could you impress? could he impress? could we impress? could you impress? could they impress?
V-ing form
could I be impressing? could you be impressing? could he be impressing? could we be impressing? could you be impressing? could they be impressing?
Perfect
could I have impressed? could you have impressed? could he have impressed? could we have impressed? could you have impressed? could they have impressed?
V-ing perfect
could I have been impressing? could you have been impressing? could he have been impressing? could we have been impressing? could you have been impressing? could they have been impressing?
Interro-negative form
Simple form
couldn't I impress? couldn't you impress? couldn't he impress? couldn't we impress? couldn't you impress? couldn't they impress?
V-ing form
couldn't I be impressing? couldn't you be impressing? couldn't he be impressing? couldn't we be impressing? couldn't you be impressing? couldn't they be impressing?
Perfect
couldn't I have impressed? couldn't you have impressed? couldn't he have impressed? couldn't we have impressed? couldn't you have impressed? couldn't they have impressed?
V-ing perfect
couldn't I have been impressing? couldn't you have been impressing? couldn't he have been impressing? couldn't we have been impressing? couldn't you have been impressing? couldn't they have been impressing?