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