English verb conjugation
MUST LAUGH

Regular verb: laugh - laughed - laughed

Affirmation

Simple form	V-ing form
I must laugh you must laugh she must laugh we must laugh you must laugh they must laugh	I must be laughing you must be laughing she must be laughing we must be laughing you must be laughing they must be laughing
Perfect	V-ing perfect
I must have laughed you must have laughed she must have laughed we must have laughed you must have laughed they must have laughed	I must have been laughing you must have been laughing she must have been laughing we must have been laughing you must have been laughing they must have been laughing

Negation

Simple form	V-ing form
I mustn't laugh you mustn't laugh she mustn't laugh we mustn't laugh you mustn't laugh they mustn't laugh	I mustn't be laughing you mustn't be laughing she mustn't be laughing we mustn't be laughing you mustn't be laughing they mustn't be laughing
Perfect	V-ing perfect
I mustn't have laughed you mustn't have laughed she mustn't have laughed we mustn't have laughed you mustn't have laughed they mustn't have laughed	I mustn't have been laughing you mustn't have been laughing she mustn't have been laughing we mustn't have been laughing you mustn't have been laughing they mustn't have been laughing

Interrogative form

Simple form	V-ing form
must I laugh? must you laugh? must she laugh? must we laugh? must you laugh? must they laugh?	must I be laughing? must you be laughing? must she be laughing? must we be laughing? must you be laughing? must they be laughing?
Perfect	V-ing perfect
must I have laughed? must you have laughed? must she have laughed? must we have laughed? must you have laughed? must they have laughed?	must I have been laughing? must you have been laughing? must she have been laughing? must we have been laughing? must you have been laughing? must they have been laughing?

Interro-negative form

Simple form	V-ing form
mustn't I laugh? mustn't you laugh? mustn't she laugh? mustn't we laugh? mustn't you laugh? mustn't they laugh?	mustn't I be laughing? mustn't you be laughing? mustn't she be laughing? mustn't we be laughing? mustn't you be laughing? mustn't they be laughing?
Perfect	V-ing perfect
mustn't I have laughed? mustn't you have laughed? mustn't she have laughed? mustn't we have laughed? mustn't you have laughed? mustn't they have laughed?	mustn't I have been laughing? mustn't you have been laughing? mustn't she have been laughing? mustn't we have been laughing? mustn't you have been laughing? mustn't they have been laughing?