English verb conjugation
MUST SERVE

Regular verb: serve - served - served

Affirmation

Simple form	V-ing form
I must serve you must serve she must serve we must serve you must serve they must serve	I must be serving you must be serving she must be serving we must be serving you must be serving they must be serving
Perfect	V-ing perfect
I must have served you must have served she must have served we must have served you must have served they must have served	I must have been serving you must have been serving she must have been serving we must have been serving you must have been serving they must have been serving

Negation

Simple form	V-ing form
I mustn't serve you mustn't serve she mustn't serve we mustn't serve you mustn't serve they mustn't serve	I mustn't be serving you mustn't be serving she mustn't be serving we mustn't be serving you mustn't be serving they mustn't be serving
Perfect	V-ing perfect
I mustn't have served you mustn't have served she mustn't have served we mustn't have served you mustn't have served they mustn't have served	I mustn't have been serving you mustn't have been serving she mustn't have been serving we mustn't have been serving you mustn't have been serving they mustn't have been serving

Interrogative form

Simple form	V-ing form
must I serve? must you serve? must she serve? must we serve? must you serve? must they serve?	must I be serving? must you be serving? must she be serving? must we be serving? must you be serving? must they be serving?
Perfect	V-ing perfect
must I have served? must you have served? must she have served? must we have served? must you have served? must they have served?	must I have been serving? must you have been serving? must she have been serving? must we have been serving? must you have been serving? must they have been serving?

Interro-negative form

Simple form	V-ing form
mustn't I serve? mustn't you serve? mustn't she serve? mustn't we serve? mustn't you serve? mustn't they serve?	mustn't I be serving? mustn't you be serving? mustn't she be serving? mustn't we be serving? mustn't you be serving? mustn't they be serving?
Perfect	V-ing perfect
mustn't I have served? mustn't you have served? mustn't she have served? mustn't we have served? mustn't you have served? mustn't they have served?	mustn't I have been serving? mustn't you have been serving? mustn't she have been serving? mustn't we have been serving? mustn't you have been serving? mustn't they have been serving?