I can refuel you can refuel she can refuel we can refuel you can refuel they can refuel
V-ing form
I can be refuelling you can be refuelling she can be refuelling we can be refuelling you can be refuelling they can be refuelling
Perfect
I can have refuelled you can have refuelled she can have refuelled we can have refuelled you can have refuelled they can have refuelled
V-ing perfect
I can have been refuelling you can have been refuelling she can have been refuelling we can have been refuelling you can have been refuelling they can have been refuelling
Negation
Simple form
I cannot refuel you cannot refuel she cannot refuel we cannot refuel you cannot refuel they cannot refuel
V-ing form
I cannot be refuelling you cannot be refuelling she cannot be refuelling we cannot be refuelling you cannot be refuelling they cannot be refuelling
Perfect
I cannot have refuelled you cannot have refuelled she cannot have refuelled we cannot have refuelled you cannot have refuelled they cannot have refuelled
V-ing perfect
I cannot have been refuelling you cannot have been refuelling she cannot have been refuelling we cannot have been refuelling you cannot have been refuelling they cannot have been refuelling
Interrogative form
Simple form
can I refuel? can you refuel? can she refuel? can we refuel? can you refuel? can they refuel?
V-ing form
can I be refuelling? can you be refuelling? can she be refuelling? can we be refuelling? can you be refuelling? can they be refuelling?
Perfect
can I have refuelled? can you have refuelled? can she have refuelled? can we have refuelled? can you have refuelled? can they have refuelled?
V-ing perfect
can I have been refuelling? can you have been refuelling? can she have been refuelling? can we have been refuelling? can you have been refuelling? can they have been refuelling?
Interro-negative form
Simple form
can I not refuel? can you not refuel? can she not refuel? can we not refuel? can you not refuel? can they not refuel?
V-ing form
can I not be refuelling? can you not be refuelling? can she not be refuelling? can we not be refuelling? can you not be refuelling? can they not be refuelling?
Perfect
can I not have refuelled? can you not have refuelled? can she not have refuelled? can we not have refuelled? can you not have refuelled? can they not have refuelled?
V-ing perfect
can I not have been refuelling? can you not have been refuelling? can she not have been refuelling? can we not have been refuelling? can you not have been refuelling? can they not have been refuelling?