I could nickel you could nickel he could nickel we could nickel you could nickel they could nickel
V-ing form
I could be nickelling you could be nickelling he could be nickelling we could be nickelling you could be nickelling they could be nickelling
Perfect
I could have nickelled you could have nickelled he could have nickelled we could have nickelled you could have nickelled they could have nickelled
V-ing perfect
I could have been nickelling you could have been nickelling he could have been nickelling we could have been nickelling you could have been nickelling they could have been nickelling
Negation
Simple form
I couldn't nickel you couldn't nickel he couldn't nickel we couldn't nickel you couldn't nickel they couldn't nickel
V-ing form
I couldn't be nickelling you couldn't be nickelling he couldn't be nickelling we couldn't be nickelling you couldn't be nickelling they couldn't be nickelling
Perfect
I couldn't have nickelled you couldn't have nickelled he couldn't have nickelled we couldn't have nickelled you couldn't have nickelled they couldn't have nickelled
V-ing perfect
I couldn't have been nickelling you couldn't have been nickelling he couldn't have been nickelling we couldn't have been nickelling you couldn't have been nickelling they couldn't have been nickelling
Interrogative form
Simple form
could I nickel? could you nickel? could he nickel? could we nickel? could you nickel? could they nickel?
V-ing form
could I be nickelling? could you be nickelling? could he be nickelling? could we be nickelling? could you be nickelling? could they be nickelling?
Perfect
could I have nickelled? could you have nickelled? could he have nickelled? could we have nickelled? could you have nickelled? could they have nickelled?
V-ing perfect
could I have been nickelling? could you have been nickelling? could he have been nickelling? could we have been nickelling? could you have been nickelling? could they have been nickelling?
Interro-negative form
Simple form
couldn't I nickel? couldn't you nickel? couldn't he nickel? couldn't we nickel? couldn't you nickel? couldn't they nickel?
V-ing form
couldn't I be nickelling? couldn't you be nickelling? couldn't he be nickelling? couldn't we be nickelling? couldn't you be nickelling? couldn't they be nickelling?
Perfect
couldn't I have nickelled? couldn't you have nickelled? couldn't he have nickelled? couldn't we have nickelled? couldn't you have nickelled? couldn't they have nickelled?
V-ing perfect
couldn't I have been nickelling? couldn't you have been nickelling? couldn't he have been nickelling? couldn't we have been nickelling? couldn't you have been nickelling? couldn't they have been nickelling?