I can assign you can assign he can assign we can assign you can assign they can assign
V-ing form
I can be assigning you can be assigning he can be assigning we can be assigning you can be assigning they can be assigning
Perfect
I can have assigned you can have assigned he can have assigned we can have assigned you can have assigned they can have assigned
V-ing perfect
I can have been assigning you can have been assigning he can have been assigning we can have been assigning you can have been assigning they can have been assigning
Negation
Simple form
I can't assign you can't assign he can't assign we can't assign you can't assign they can't assign
V-ing form
I can't be assigning you can't be assigning he can't be assigning we can't be assigning you can't be assigning they can't be assigning
Perfect
I can't have assigned you can't have assigned he can't have assigned we can't have assigned you can't have assigned they can't have assigned
V-ing perfect
I can't have been assigning you can't have been assigning he can't have been assigning we can't have been assigning you can't have been assigning they can't have been assigning
Interrogative form
Simple form
can I assign? can you assign? can he assign? can we assign? can you assign? can they assign?
V-ing form
can I be assigning? can you be assigning? can he be assigning? can we be assigning? can you be assigning? can they be assigning?
Perfect
can I have assigned? can you have assigned? can he have assigned? can we have assigned? can you have assigned? can they have assigned?
V-ing perfect
can I have been assigning? can you have been assigning? can he have been assigning? can we have been assigning? can you have been assigning? can they have been assigning?
Interro-negative form
Simple form
can't I assign? can't you assign? can't he assign? can't we assign? can't you assign? can't they assign?
V-ing form
can't I be assigning? can't you be assigning? can't he be assigning? can't we be assigning? can't you be assigning? can't they be assigning?
Perfect
can't I have assigned? can't you have assigned? can't he have assigned? can't we have assigned? can't you have assigned? can't they have assigned?
V-ing perfect
can't I have been assigning? can't you have been assigning? can't he have been assigning? can't we have been assigning? can't you have been assigning? can't they have been assigning?