English verb conjugation
COULD MIX

Regular verb: mix - mixed - mixed

Affirmation

Simple form	V-ing form
I could mix you could mix he could mix we could mix you could mix they could mix	I could be mixing you could be mixing he could be mixing we could be mixing you could be mixing they could be mixing
Perfect	V-ing perfect
I could have mixed you could have mixed he could have mixed we could have mixed you could have mixed they could have mixed	I could have been mixing you could have been mixing he could have been mixing we could have been mixing you could have been mixing they could have been mixing

Negation

Simple form	V-ing form
I could not mix you could not mix he could not mix we could not mix you could not mix they could not mix	I could not be mixing you could not be mixing he could not be mixing we could not be mixing you could not be mixing they could not be mixing
Perfect	V-ing perfect
I could not have mixed you could not have mixed he could not have mixed we could not have mixed you could not have mixed they could not have mixed	I could not have been mixing you could not have been mixing he could not have been mixing we could not have been mixing you could not have been mixing they could not have been mixing

Interrogative form

Simple form	V-ing form
could I mix? could you mix? could he mix? could we mix? could you mix? could they mix?	could I be mixing? could you be mixing? could he be mixing? could we be mixing? could you be mixing? could they be mixing?
Perfect	V-ing perfect
could I have mixed? could you have mixed? could he have mixed? could we have mixed? could you have mixed? could they have mixed?	could I have been mixing? could you have been mixing? could he have been mixing? could we have been mixing? could you have been mixing? could they have been mixing?

Interro-negative form

Simple form	V-ing form
could I not mix? could you not mix? could he not mix? could we not mix? could you not mix? could they not mix?	could I not be mixing? could you not be mixing? could he not be mixing? could we not be mixing? could you not be mixing? could they not be mixing?
Perfect	V-ing perfect
could I not have mixed? could you not have mixed? could he not have mixed? could we not have mixed? could you not have mixed? could they not have mixed?	could I not have been mixing? could you not have been mixing? could he not have been mixing? could we not have been mixing? could you not have been mixing? could they not have been mixing?