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