English verb conjugation
COULD BACKDATE

Regular verb: backdate - backdated - backdated

Affirmation

Simple form	V-ing form
I could backdate you could backdate she could backdate we could backdate you could backdate they could backdate	I could be backdating you could be backdating she could be backdating we could be backdating you could be backdating they could be backdating
Perfect	V-ing perfect
I could have backdated you could have backdated she could have backdated we could have backdated you could have backdated they could have backdated	I could have been backdating you could have been backdating she could have been backdating we could have been backdating you could have been backdating they could have been backdating

Negation

Simple form	V-ing form
I couldn't backdate you couldn't backdate she couldn't backdate we couldn't backdate you couldn't backdate they couldn't backdate	I couldn't be backdating you couldn't be backdating she couldn't be backdating we couldn't be backdating you couldn't be backdating they couldn't be backdating
Perfect	V-ing perfect
I couldn't have backdated you couldn't have backdated she couldn't have backdated we couldn't have backdated you couldn't have backdated they couldn't have backdated	I couldn't have been backdating you couldn't have been backdating she couldn't have been backdating we couldn't have been backdating you couldn't have been backdating they couldn't have been backdating

Interrogative form

Simple form	V-ing form
could I backdate? could you backdate? could she backdate? could we backdate? could you backdate? could they backdate?	could I be backdating? could you be backdating? could she be backdating? could we be backdating? could you be backdating? could they be backdating?
Perfect	V-ing perfect
could I have backdated? could you have backdated? could she have backdated? could we have backdated? could you have backdated? could they have backdated?	could I have been backdating? could you have been backdating? could she have been backdating? could we have been backdating? could you have been backdating? could they have been backdating?

Interro-negative form

Simple form	V-ing form
couldn't I backdate? couldn't you backdate? couldn't she backdate? couldn't we backdate? couldn't you backdate? couldn't they backdate?	couldn't I be backdating? couldn't you be backdating? couldn't she be backdating? couldn't we be backdating? couldn't you be backdating? couldn't they be backdating?
Perfect	V-ing perfect
couldn't I have backdated? couldn't you have backdated? couldn't she have backdated? couldn't we have backdated? couldn't you have backdated? couldn't they have backdated?	couldn't I have been backdating? couldn't you have been backdating? couldn't she have been backdating? couldn't we have been backdating? couldn't you have been backdating? couldn't they have been backdating?