I must cool you must cool she must cool we must cool you must cool they must cool
V-ing form
I must be cooling you must be cooling she must be cooling we must be cooling you must be cooling they must be cooling
Perfect
I must have cooled you must have cooled she must have cooled we must have cooled you must have cooled they must have cooled
V-ing perfect
I must have been cooling you must have been cooling she must have been cooling we must have been cooling you must have been cooling they must have been cooling
Negation
Simple form
I must not cool you must not cool she must not cool we must not cool you must not cool they must not cool
V-ing form
I must not be cooling you must not be cooling she must not be cooling we must not be cooling you must not be cooling they must not be cooling
Perfect
I must not have cooled you must not have cooled she must not have cooled we must not have cooled you must not have cooled they must not have cooled
V-ing perfect
I must not have been cooling you must not have been cooling she must not have been cooling we must not have been cooling you must not have been cooling they must not have been cooling
Interrogative form
Simple form
must I cool? must you cool? must she cool? must we cool? must you cool? must they cool?
V-ing form
must I be cooling? must you be cooling? must she be cooling? must we be cooling? must you be cooling? must they be cooling?
Perfect
must I have cooled? must you have cooled? must she have cooled? must we have cooled? must you have cooled? must they have cooled?
V-ing perfect
must I have been cooling? must you have been cooling? must she have been cooling? must we have been cooling? must you have been cooling? must they have been cooling?
Interro-negative form
Simple form
must I not cool? must you not cool? must she not cool? must we not cool? must you not cool? must they not cool?
V-ing form
must I not be cooling? must you not be cooling? must she not be cooling? must we not be cooling? must you not be cooling? must they not be cooling?
Perfect
must I not have cooled? must you not have cooled? must she not have cooled? must we not have cooled? must you not have cooled? must they not have cooled?
V-ing perfect
must I not have been cooling? must you not have been cooling? must she not have been cooling? must we not have been cooling? must you not have been cooling? must they not have been cooling?