must ventilate
Regular verb: ventilate - ventilated- ventilated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must ventilate
you must ventilate
she must ventilate
we must ventilate
you must ventilate
they must ventilate 	I must be ventilating
you must be ventilating
she must be ventilating
we must be ventilating
you must be ventilating
they must be ventilating	I must have ventilated
you must have ventilated
she must have ventilated
we must have ventilated
you must have ventilated
they must have ventilated	I must have been ventilating
you must have been ventilating
she must have been ventilating
we must have been ventilating
you must have been ventilating
they must have been ventilating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't ventilate
you mustn't ventilate
she mustn't ventilate
we mustn't ventilate
you mustn't ventilate
they mustn't ventilate 	I mustn't be ventilating
you mustn't be ventilating
she mustn't be ventilating
we mustn't be ventilating
you mustn't be ventilating
they mustn't be ventilating	I mustn't have ventilated
you mustn't have ventilated
she mustn't have ventilated
we mustn't have ventilated
you mustn't have ventilated
they mustn't have ventilated	I mustn't have been ventilating
you mustn't have been ventilating
she mustn't have been ventilating
we mustn't have been ventilating
you mustn't have been ventilating
they mustn't have been ventilating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I ventilate?
must you ventilate?
must she ventilate?
must we ventilate?
must you ventilate?
must they ventilate? 	must I be ventilating?
must you be ventilating?
must she be ventilating?
must we be ventilating?
must you be ventilating?
must they be ventilating? 	must I have ventilated?
must you have ventilated?
must she have ventilated?
must we have ventilated?
must you have ventilated?
must they have ventilated? 	must I have been ventilating?
must you have been ventilating?
must she have been ventilating?
must we have been ventilating?
must you have been ventilating?
must they have been ventilating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I ventilate?
mustn't you ventilate?
mustn't she ventilate?
mustn't we ventilate?
mustn't you ventilate?
mustn't they ventilate? 	mustn't I be ventilating?
mustn't you be ventilating?
mustn't she be ventilating?
mustn't we be ventilating?
mustn't you be ventilating?
mustn't they be ventilating? 	mustn't I have ventilated?
mustn't you have ventilated?
mustn't she have ventilated?
mustn't we have ventilated?
mustn't you have ventilated?
mustn't they have ventilated? 	mustn't I have been ventilating?
mustn't you have been ventilating?
mustn't she have been ventilating?
mustn't we have been ventilating?
mustn't you have been ventilating?
mustn't they have been ventilating?