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 mustn't cool you mustn't cool she mustn't cool we mustn't cool you mustn't cool they mustn't cool
V-ing form
I mustn't be cooling you mustn't be cooling she mustn't be cooling we mustn't be cooling you mustn't be cooling they mustn't be cooling
Perfect
I mustn't have cooled you mustn't have cooled she mustn't have cooled we mustn't have cooled you mustn't have cooled they mustn't have cooled
V-ing perfect
I mustn't have been cooling you mustn't have been cooling she mustn't have been cooling we mustn't have been cooling you mustn't have been cooling they mustn't 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
mustn't I cool? mustn't you cool? mustn't she cool? mustn't we cool? mustn't you cool? mustn't they cool?
V-ing form
mustn't I be cooling? mustn't you be cooling? mustn't she be cooling? mustn't we be cooling? mustn't you be cooling? mustn't they be cooling?
Perfect
mustn't I have cooled? mustn't you have cooled? mustn't she have cooled? mustn't we have cooled? mustn't you have cooled? mustn't they have cooled?
V-ing perfect
mustn't I have been cooling? mustn't you have been cooling? mustn't she have been cooling? mustn't we have been cooling? mustn't you have been cooling? mustn't they have been cooling?