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