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