I could donate you could donate he could donate we could donate you could donate they could donate
V-ing form
I could be donating you could be donating he could be donating we could be donating you could be donating they could be donating
Perfect
I could have donated you could have donated he 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 he could have been donating we could have been donating you could have been donating they could have been donating
Negation
Simple form
I could not donate you could not donate he could not donate we could not donate you could not donate they could not donate
V-ing form
I could not be donating you could not be donating he could not be donating we could not be donating you could not be donating they could not be donating
Perfect
I could not have donated you could not have donated he could not have donated we could not have donated you could not have donated they could not have donated
V-ing perfect
I could not have been donating you could not have been donating he could not have been donating we could not have been donating you could not have been donating they could not have been donating
Interrogative form
Simple form
could I donate? could you donate? could he donate? could we donate? could you donate? could they donate?
V-ing form
could I be donating? could you be donating? could he be donating? could we be donating? could you be donating? could they be donating?
Perfect
could I have donated? could you have donated? could he 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 he have been donating? could we have been donating? could you have been donating? could they have been donating?
Interro-negative form
Simple form
could I not donate? could you not donate? could he not donate? could we not donate? could you not donate? could they not donate?
V-ing form
could I not be donating? could you not be donating? could he not be donating? could we not be donating? could you not be donating? could they not be donating?
Perfect
could I not have donated? could you not have donated? could he not have donated? could we not have donated? could you not have donated? could they not have donated?
V-ing perfect
could I not have been donating? could you not have been donating? could he not have been donating? could we not have been donating? could you not have been donating? could they not have been donating?