I must gush you must gush he must gush we must gush you must gush they must gush
V-ing form
I must be gushing you must be gushing he must be gushing we must be gushing you must be gushing they must be gushing
Perfect
I must have gushed you must have gushed he must have gushed we must have gushed you must have gushed they must have gushed
V-ing perfect
I must have been gushing you must have been gushing he must have been gushing we must have been gushing you must have been gushing they must have been gushing
Negation
Simple form
I mustn't gush you mustn't gush he mustn't gush we mustn't gush you mustn't gush they mustn't gush
V-ing form
I mustn't be gushing you mustn't be gushing he mustn't be gushing we mustn't be gushing you mustn't be gushing they mustn't be gushing
Perfect
I mustn't have gushed you mustn't have gushed he mustn't have gushed we mustn't have gushed you mustn't have gushed they mustn't have gushed
V-ing perfect
I mustn't have been gushing you mustn't have been gushing he mustn't have been gushing we mustn't have been gushing you mustn't have been gushing they mustn't have been gushing
Interrogative form
Simple form
must I gush? must you gush? must he gush? must we gush? must you gush? must they gush?
V-ing form
must I be gushing? must you be gushing? must he be gushing? must we be gushing? must you be gushing? must they be gushing?
Perfect
must I have gushed? must you have gushed? must he have gushed? must we have gushed? must you have gushed? must they have gushed?
V-ing perfect
must I have been gushing? must you have been gushing? must he have been gushing? must we have been gushing? must you have been gushing? must they have been gushing?
Interro-negative form
Simple form
mustn't I gush? mustn't you gush? mustn't he gush? mustn't we gush? mustn't you gush? mustn't they gush?
V-ing form
mustn't I be gushing? mustn't you be gushing? mustn't he be gushing? mustn't we be gushing? mustn't you be gushing? mustn't they be gushing?
Perfect
mustn't I have gushed? mustn't you have gushed? mustn't he have gushed? mustn't we have gushed? mustn't you have gushed? mustn't they have gushed?
V-ing perfect
mustn't I have been gushing? mustn't you have been gushing? mustn't he have been gushing? mustn't we have been gushing? mustn't you have been gushing? mustn't they have been gushing?