I'll be backdating you'll be backdating he'll be backdating we'll be backdating you'll be backdating they'll be backdating
Perfect
I'll have backdated you'll have backdated he'll have backdated we'll have backdated you'll have backdated they'll have backdated
V-ing perfect
I'll have been backdating you'll have been backdating he'll have been backdating we'll have been backdating you'll have been backdating they'll have been backdating
Negation
Simple form
I shan't backdate you shan't backdate he shan't backdate we shan't backdate you shan't backdate they shan't backdate
V-ing form
I shan't be backdating you shan't be backdating he shan't be backdating we shan't be backdating you shan't be backdating they shan't be backdating
Perfect
I shan't have backdated you shan't have backdated he shan't have backdated we shan't have backdated you shan't have backdated they shan't have backdated
V-ing perfect
I shan't have been backdating you shan't have been backdating he shan't have been backdating we shan't have been backdating you shan't have been backdating they shan't have been backdating
Interrogative form
Simple form
shall I backdate? shall you backdate? shall he backdate? shall we backdate? shall you backdate? shall they backdate?
V-ing form
shall I be backdating? shall you be backdating? shall he be backdating? shall we be backdating? shall you be backdating? shall they be backdating?
Perfect
shall I have backdated? shall you have backdated? shall he have backdated? shall we have backdated? shall you have backdated? shall they have backdated?
V-ing perfect
shall I have been backdating? shall you have been backdating? shall he have been backdating? shall we have been backdating? shall you have been backdating? shall they have been backdating?
Interro-negative form
Simple form
shan't I backdate? shan't you backdate? shan't he backdate? shan't we backdate? shan't you backdate? shan't they backdate?
V-ing form
shan't I be backdating? shan't you be backdating? shan't he be backdating? shan't we be backdating? shan't you be backdating? shan't they be backdating?
Perfect
shan't I have backdated? shan't you have backdated? shan't he have backdated? shan't we have backdated? shan't you have backdated? shan't they have backdated?
V-ing perfect
shan't I have been backdating? shan't you have been backdating? shan't he have been backdating? shan't we have been backdating? shan't you have been backdating? shan't they have been backdating?