I could enamel you could enamel he could enamel we could enamel you could enamel they could enamel
V-ing form
I could be enamelling you could be enamelling he could be enamelling we could be enamelling you could be enamelling they could be enamelling
Perfect
I could have enamelled you could have enamelled he could have enamelled we could have enamelled you could have enamelled they could have enamelled
V-ing perfect
I could have been enamelling you could have been enamelling he could have been enamelling we could have been enamelling you could have been enamelling they could have been enamelling
Negation
Simple form
I could not enamel you could not enamel he could not enamel we could not enamel you could not enamel they could not enamel
V-ing form
I could not be enamelling you could not be enamelling he could not be enamelling we could not be enamelling you could not be enamelling they could not be enamelling
Perfect
I could not have enamelled you could not have enamelled he could not have enamelled we could not have enamelled you could not have enamelled they could not have enamelled
V-ing perfect
I could not have been enamelling you could not have been enamelling he could not have been enamelling we could not have been enamelling you could not have been enamelling they could not have been enamelling
Interrogative form
Simple form
could I enamel? could you enamel? could he enamel? could we enamel? could you enamel? could they enamel?
V-ing form
could I be enamelling? could you be enamelling? could he be enamelling? could we be enamelling? could you be enamelling? could they be enamelling?
Perfect
could I have enamelled? could you have enamelled? could he have enamelled? could we have enamelled? could you have enamelled? could they have enamelled?
V-ing perfect
could I have been enamelling? could you have been enamelling? could he have been enamelling? could we have been enamelling? could you have been enamelling? could they have been enamelling?
Interro-negative form
Simple form
could I not enamel? could you not enamel? could he not enamel? could we not enamel? could you not enamel? could they not enamel?
V-ing form
could I not be enamelling? could you not be enamelling? could he not be enamelling? could we not be enamelling? could you not be enamelling? could they not be enamelling?
Perfect
could I not have enamelled? could you not have enamelled? could he not have enamelled? could we not have enamelled? could you not have enamelled? could they not have enamelled?
V-ing perfect
could I not have been enamelling? could you not have been enamelling? could he not have been enamelling? could we not have been enamelling? could you not have been enamelling? could they not have been enamelling?