English verb conjugation
COULD BITTER

Regular verb: bitter - bittered - bittered

Affirmation

Simple form	V-ing form
I could bitter you could bitter he could bitter we could bitter you could bitter they could bitter	I could be bittering you could be bittering he could be bittering we could be bittering you could be bittering they could be bittering
Perfect	V-ing perfect
I could have bittered you could have bittered he could have bittered we could have bittered you could have bittered they could have bittered	I could have been bittering you could have been bittering he could have been bittering we could have been bittering you could have been bittering they could have been bittering

Negation

Simple form	V-ing form
I could not bitter you could not bitter he could not bitter we could not bitter you could not bitter they could not bitter	I could not be bittering you could not be bittering he could not be bittering we could not be bittering you could not be bittering they could not be bittering
Perfect	V-ing perfect
I could not have bittered you could not have bittered he could not have bittered we could not have bittered you could not have bittered they could not have bittered	I could not have been bittering you could not have been bittering he could not have been bittering we could not have been bittering you could not have been bittering they could not have been bittering

Interrogative form

Simple form	V-ing form
could I bitter? could you bitter? could he bitter? could we bitter? could you bitter? could they bitter?	could I be bittering? could you be bittering? could he be bittering? could we be bittering? could you be bittering? could they be bittering?
Perfect	V-ing perfect
could I have bittered? could you have bittered? could he have bittered? could we have bittered? could you have bittered? could they have bittered?	could I have been bittering? could you have been bittering? could he have been bittering? could we have been bittering? could you have been bittering? could they have been bittering?

Interro-negative form

Simple form	V-ing form
could I not bitter? could you not bitter? could he not bitter? could we not bitter? could you not bitter? could they not bitter?	could I not be bittering? could you not be bittering? could he not be bittering? could we not be bittering? could you not be bittering? could they not be bittering?
Perfect	V-ing perfect
could I not have bittered? could you not have bittered? could he not have bittered? could we not have bittered? could you not have bittered? could they not have bittered?	could I not have been bittering? could you not have been bittering? could he not have been bittering? could we not have been bittering? could you not have been bittering? could they not have been bittering?