I should alter you should alter he should alter we should alter you should alter they should alter
V-ing form
I should be altering you should be altering he should be altering we should be altering you should be altering they should be altering
Perfect
I should have altered you should have altered he should have altered we should have altered you should have altered they should have altered
V-ing perfect
I should have been altering you should have been altering he should have been altering we should have been altering you should have been altering they should have been altering
Negation
Simple form
I should not alter you should not alter he should not alter we should not alter you should not alter they should not alter
V-ing form
I should not be altering you should not be altering he should not be altering we should not be altering you should not be altering they should not be altering
Perfect
I should not have altered you should not have altered he should not have altered we should not have altered you should not have altered they should not have altered
V-ing perfect
I should not have been altering you should not have been altering he should not have been altering we should not have been altering you should not have been altering they should not have been altering
Interrogative form
Simple form
should I alter? should you alter? should he alter? should we alter? should you alter? should they alter?
V-ing form
should I be altering? should you be altering? should he be altering? should we be altering? should you be altering? should they be altering?
Perfect
should I have altered? should you have altered? should he have altered? should we have altered? should you have altered? should they have altered?
V-ing perfect
should I have been altering? should you have been altering? should he have been altering? should we have been altering? should you have been altering? should they have been altering?
Interro-negative form
Simple form
should I not alter? should you not alter? should he not alter? should we not alter? should you not alter? should they not alter?
V-ing form
should I not be altering? should you not be altering? should he not be altering? should we not be altering? should you not be altering? should they not be altering?
Perfect
should I not have altered? should you not have altered? should he not have altered? should we not have altered? should you not have altered? should they not have altered?
V-ing perfect
should I not have been altering? should you not have been altering? should he not have been altering? should we not have been altering? should you not have been altering? should they not have been altering?