I'd been altering you'd been altering he'd been altering we'd been altering you'd been altering they'd been altering
Future
I'll alter you'll alter he'll alter we'll alter you'll alter they'll alter
Future continuous
I'll be altering you'll be altering he'll be altering we'll be altering you'll be altering they'll be altering
Future perfect
I'll have altered you'll have altered he'll have altered we'll have altered you'll have altered they'll have altered
Future perfect continuous
I'll have been altering you'll have been altering he'll have been altering we'll have been altering you'll have been altering they'll have been altering
Conditional
Present
I'd alter you'd alter he'd alter we'd alter you'd alter they'd alter
Present continuous
I'd be altering you'd be altering he'd be altering we'd be altering you'd be altering they'd be altering
Past
I'd have altered you'd have altered he'd have altered we'd have altered you'd have altered they'd have altered
Past continuous
I'd have been altering you'd have been altering he'd have been altering we'd have been altering you'd have been altering they'd have been altering