English verb conjugation
CAN BACKDATE

Regular verb: backdate - backdated - backdated

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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