must endow
Regular verb: endow - endowed- endowed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must endow
you must endow
she must endow
we must endow
you must endow
they must endow 	I must be endowing
you must be endowing
she must be endowing
we must be endowing
you must be endowing
they must be endowing	I must have endowed
you must have endowed
she must have endowed
we must have endowed
you must have endowed
they must have endowed	I must have been endowing
you must have been endowing
she must have been endowing
we must have been endowing
you must have been endowing
they must have been endowing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't endow
you mustn't endow
she mustn't endow
we mustn't endow
you mustn't endow
they mustn't endow 	I mustn't be endowing
you mustn't be endowing
she mustn't be endowing
we mustn't be endowing
you mustn't be endowing
they mustn't be endowing	I mustn't have endowed
you mustn't have endowed
she mustn't have endowed
we mustn't have endowed
you mustn't have endowed
they mustn't have endowed	I mustn't have been endowing
you mustn't have been endowing
she mustn't have been endowing
we mustn't have been endowing
you mustn't have been endowing
they mustn't have been endowing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I endow?
must you endow?
must she endow?
must we endow?
must you endow?
must they endow? 	must I be endowing?
must you be endowing?
must she be endowing?
must we be endowing?
must you be endowing?
must they be endowing? 	must I have endowed?
must you have endowed?
must she have endowed?
must we have endowed?
must you have endowed?
must they have endowed? 	must I have been endowing?
must you have been endowing?
must she have been endowing?
must we have been endowing?
must you have been endowing?
must they have been endowing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I endow?
mustn't you endow?
mustn't she endow?
mustn't we endow?
mustn't you endow?
mustn't they endow? 	mustn't I be endowing?
mustn't you be endowing?
mustn't she be endowing?
mustn't we be endowing?
mustn't you be endowing?
mustn't they be endowing? 	mustn't I have endowed?
mustn't you have endowed?
mustn't she have endowed?
mustn't we have endowed?
mustn't you have endowed?
mustn't they have endowed? 	mustn't I have been endowing?
mustn't you have been endowing?
mustn't she have been endowing?
mustn't we have been endowing?
mustn't you have been endowing?
mustn't they have been endowing?