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