English verb conjugation
MUST ALTER

Regular verb: alter - altered - altered

Affirmation

Simple form	V-ing form
I must alter you must alter he must alter we must alter you must alter they must alter	I must be altering you must be altering he must be altering we must be altering you must be altering they must be altering
Perfect	V-ing perfect
I must have altered you must have altered he must have altered we must have altered you must have altered they must have altered	I must have been altering you must have been altering he must have been altering we must have been altering you must have been altering they must have been altering

Negation

Simple form	V-ing form
I mustn't alter you mustn't alter he mustn't alter we mustn't alter you mustn't alter they mustn't alter	I mustn't be altering you mustn't be altering he mustn't be altering we mustn't be altering you mustn't be altering they mustn't be altering
Perfect	V-ing perfect
I mustn't have altered you mustn't have altered he mustn't have altered we mustn't have altered you mustn't have altered they mustn't have altered	I mustn't have been altering you mustn't have been altering he mustn't have been altering we mustn't have been altering you mustn't have been altering they mustn't have been altering

Interrogative form

Simple form	V-ing form
must I alter? must you alter? must he alter? must we alter? must you alter? must they alter?	must I be altering? must you be altering? must he be altering? must we be altering? must you be altering? must they be altering?
Perfect	V-ing perfect
must I have altered? must you have altered? must he have altered? must we have altered? must you have altered? must they have altered?	must I have been altering? must you have been altering? must he have been altering? must we have been altering? must you have been altering? must they have been altering?

Interro-negative form

Simple form	V-ing form
mustn't I alter? mustn't you alter? mustn't he alter? mustn't we alter? mustn't you alter? mustn't they alter?	mustn't I be altering? mustn't you be altering? mustn't he be altering? mustn't we be altering? mustn't you be altering? mustn't they be altering?
Perfect	V-ing perfect
mustn't I have altered? mustn't you have altered? mustn't he have altered? mustn't we have altered? mustn't you have altered? mustn't they have altered?	mustn't I have been altering? mustn't you have been altering? mustn't he have been altering? mustn't we have been altering? mustn't you have been altering? mustn't they have been altering?