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