must contain
Regular verb: contain - contained- contained

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must contain
you must contain
she must contain
we must contain
you must contain
they must contain 	I must be containing
you must be containing
she must be containing
we must be containing
you must be containing
they must be containing	I must have contained
you must have contained
she must have contained
we must have contained
you must have contained
they must have contained	I must have been containing
you must have been containing
she must have been containing
we must have been containing
you must have been containing
they must have been containing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not contain
you must not contain
she must not contain
we must not contain
you must not contain
they must not contain 	I must not be containing
you must not be containing
she must not be containing
we must not be containing
you must not be containing
they must not be containing	I must not have contained
you must not have contained
she must not have contained
we must not have contained
you must not have contained
they must not have contained	I must not have been containing
you must not have been containing
she must not have been containing
we must not have been containing
you must not have been containing
they must not have been containing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I contain?
must you contain?
must she contain?
must we contain?
must you contain?
must they contain? 	must I be containing?
must you be containing?
must she be containing?
must we be containing?
must you be containing?
must they be containing? 	must I have contained?
must you have contained?
must she have contained?
must we have contained?
must you have contained?
must they have contained? 	must I have been containing?
must you have been containing?
must she have been containing?
must we have been containing?
must you have been containing?
must they have been containing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not contain?
must you not contain?
must she not contain?
must we not contain?
must you not contain?
must they not contain? 	must I not be containing?
must you not be containing?
must she not be containing?
must we not be containing?
must you not be containing?
must they not be containing? 	must I not have contained?
must you not have contained?
must she not have contained?
must we not have contained?
must you not have contained?
must they not have contained? 	must I not have been containing?
must you not have been containing?
must she not have been containing?
must we not have been containing?
must you not have been containing?
must they not have been containing?