Regular verb: alter - altered - altered
Simple form | V-ing form |
I could alter you could alter she could alter we could alter you could alter they could alter | I could be altering you could be altering she could be altering we could be altering you could be altering they could be altering |
Perfect | V-ing perfect |
I could have altered you could have altered she could have altered we could have altered you could have altered they could have altered | I could have been altering you could have been altering she could have been altering we could have been altering you could have been altering they could have been altering |
Simple form | V-ing form |
I couldn't alter you couldn't alter she couldn't alter we couldn't alter you couldn't alter they couldn't alter | I couldn't be altering you couldn't be altering she couldn't be altering we couldn't be altering you couldn't be altering they couldn't be altering |
Perfect | V-ing perfect |
I couldn't have altered you couldn't have altered she couldn't have altered we couldn't have altered you couldn't have altered they couldn't have altered | I couldn't have been altering you couldn't have been altering she couldn't have been altering we couldn't have been altering you couldn't have been altering they couldn't have been altering |
Simple form | V-ing form |
could I alter? could you alter? could she alter? could we alter? could you alter? could they alter? | could I be altering? could you be altering? could she be altering? could we be altering? could you be altering? could they be altering? |
Perfect | V-ing perfect |
could I have altered? could you have altered? could she have altered? could we have altered? could you have altered? could they have altered? | could I have been altering? could you have been altering? could she have been altering? could we have been altering? could you have been altering? could they have been altering? |
Simple form | V-ing form |
couldn't I alter? couldn't you alter? couldn't she alter? couldn't we alter? couldn't you alter? couldn't they alter? | couldn't I be altering? couldn't you be altering? couldn't she be altering? couldn't we be altering? couldn't you be altering? couldn't they be altering? |
Perfect | V-ing perfect |
couldn't I have altered? couldn't you have altered? couldn't she have altered? couldn't we have altered? couldn't you have altered? couldn't they have altered? | couldn't I have been altering? couldn't you have been altering? couldn't she have been altering? couldn't we have been altering? couldn't you have been altering? couldn't they have been altering? |