I could refuel you could refuel he could refuel we could refuel you could refuel they could refuel
Forma con V-ing
I could be refuelling you could be refuelling he could be refuelling we could be refuelling you could be refuelling they could be refuelling
Perfecto
I could have refuelled you could have refuelled he could have refuelled we could have refuelled you could have refuelled they could have refuelled
Perfecto con V-ing
I could have been refuelling you could have been refuelling he could have been refuelling we could have been refuelling you could have been refuelling they could have been refuelling
Negación
Forma simple
I couldn't refuel you couldn't refuel he couldn't refuel we couldn't refuel you couldn't refuel they couldn't refuel
Forma con V-ing
I couldn't be refuelling you couldn't be refuelling he couldn't be refuelling we couldn't be refuelling you couldn't be refuelling they couldn't be refuelling
Perfecto
I couldn't have refuelled you couldn't have refuelled he couldn't have refuelled we couldn't have refuelled you couldn't have refuelled they couldn't have refuelled
Perfecto con V-ing
I couldn't have been refuelling you couldn't have been refuelling he couldn't have been refuelling we couldn't have been refuelling you couldn't have been refuelling they couldn't have been refuelling
Forma interrogativa
Forma simple
could I refuel? could you refuel? could he refuel? could we refuel? could you refuel? could they refuel?
Forma con V-ing
could I be refuelling? could you be refuelling? could he be refuelling? could we be refuelling? could you be refuelling? could they be refuelling?
Perfecto
could I have refuelled? could you have refuelled? could he have refuelled? could we have refuelled? could you have refuelled? could they have refuelled?
Perfecto con V-ing
could I have been refuelling? could you have been refuelling? could he have been refuelling? could we have been refuelling? could you have been refuelling? could they have been refuelling?
Forma interro-negativa
Forma simple
couldn't I refuel? couldn't you refuel? couldn't he refuel? couldn't we refuel? couldn't you refuel? couldn't they refuel?
Forma con V-ing
couldn't I be refuelling? couldn't you be refuelling? couldn't he be refuelling? couldn't we be refuelling? couldn't you be refuelling? couldn't they be refuelling?
Perfecto
couldn't I have refuelled? couldn't you have refuelled? couldn't he have refuelled? couldn't we have refuelled? couldn't you have refuelled? couldn't they have refuelled?
Perfecto con V-ing
couldn't I have been refuelling? couldn't you have been refuelling? couldn't he have been refuelling? couldn't we have been refuelling? couldn't you have been refuelling? couldn't they have been refuelling?