I alter you alter he alters we alter you alter they alter
Present continuous
I am altering you are altering he is altering we are altering you are altering they are altering
Preterite
I altered you altered he altered we altered you altered they altered
Preterite continuous
I was altering you were altering he was altering we were altering you were altering they were altering
Present perfect
I have altered you have altered he has altered we have altered you have altered they have altered
Present perfect continuous
I have been altering you have been altering he has been altering we have been altering you have been altering they have been altering
Pluperfect
I had altered you had altered he had altered we had altered you had altered they had altered
Pluperfect continuous
I had been altering you had been altering he had been altering we had been altering you had been altering they had been altering
Future
I will alter you will alter he will alter we will alter you will alter they will alter
Future continuous
I will be altering you will be altering he will be altering we will be altering you will be altering they will be altering
Future perfect
I will have altered you will have altered he will have altered we will have altered you will have altered they will have altered
Future perfect continuous
I will have been altering you will have been altering he will have been altering we will have been altering you will have been altering they will have been altering
Conditional
Present
I would alter you would alter he would alter we would alter you would alter they would alter
Present continuous
I would be altering you would be altering he would be altering we would be altering you would be altering they would be altering
Past
I would have altered you would have altered he would have altered we would have altered you would have altered they would have altered
Past continuous
I would have been altering you would have been altering he would have been altering we would have been altering you would have been altering they would have been altering