English verb conjugation
MAY ALTER

Regular verb: alter - altered - altered

Affirmation

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

Negation

Simple form	V-ing form
I may not alter you may not alter he may not alter we may not alter you may not alter they may not alter	I may not be altering you may not be altering he may not be altering we may not be altering you may not be altering they may not be altering
Perfect	V-ing perfect
I may not have altered you may not have altered he may not have altered we may not have altered you may not have altered they may not have altered	I may not have been altering you may not have been altering he may not have been altering we may not have been altering you may not have been altering they may not have been altering

Interrogative form

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

Interro-negative form

Simple form	V-ing form
may I not alter? may you not alter? may he not alter? may we not alter? may you not alter? may they not alter?	may I not be altering? may you not be altering? may he not be altering? may we not be altering? may you not be altering? may they not be altering?
Perfect	V-ing perfect
may I not have altered? may you not have altered? may he not have altered? may we not have altered? may you not have altered? may they not have altered?	may I not have been altering? may you not have been altering? may he not have been altering? may we not have been altering? may you not have been altering? may they not have been altering?