I could seat you could seat he could seat we could seat you could seat they could seat
V-ing form
I could be seating you could be seating he could be seating we could be seating you could be seating they could be seating
Perfect
I could have seated you could have seated he could have seated we could have seated you could have seated they could have seated
V-ing perfect
I could have been seating you could have been seating he could have been seating we could have been seating you could have been seating they could have been seating
Negation
Simple form
I could not seat you could not seat he could not seat we could not seat you could not seat they could not seat
V-ing form
I could not be seating you could not be seating he could not be seating we could not be seating you could not be seating they could not be seating
Perfect
I could not have seated you could not have seated he could not have seated we could not have seated you could not have seated they could not have seated
V-ing perfect
I could not have been seating you could not have been seating he could not have been seating we could not have been seating you could not have been seating they could not have been seating
Interrogative form
Simple form
could I seat? could you seat? could he seat? could we seat? could you seat? could they seat?
V-ing form
could I be seating? could you be seating? could he be seating? could we be seating? could you be seating? could they be seating?
Perfect
could I have seated? could you have seated? could he have seated? could we have seated? could you have seated? could they have seated?
V-ing perfect
could I have been seating? could you have been seating? could he have been seating? could we have been seating? could you have been seating? could they have been seating?
Interro-negative form
Simple form
could I not seat? could you not seat? could he not seat? could we not seat? could you not seat? could they not seat?
V-ing form
could I not be seating? could you not be seating? could he not be seating? could we not be seating? could you not be seating? could they not be seating?
Perfect
could I not have seated? could you not have seated? could he not have seated? could we not have seated? could you not have seated? could they not have seated?
V-ing perfect
could I not have been seating? could you not have been seating? could he not have been seating? could we not have been seating? could you not have been seating? could they not have been seating?