The Conjugator
English verb conjugation
COULD HAPPEN

Regular verb: happen - happened - happened

Affirmation

Simple form

V-ing form

-
-
it could happen
-
-
-		-
-
it could be happening
-
-
-

Perfect

V-ing perfect

-
-
it could have happened
-
-
-		-
-
it could have been happening
-
-
-

Negation

Simple form

V-ing form

-
-
it could not happen
-
-
-		-
-
it could not be happening
-
-
-

Perfect

V-ing perfect

-
-
it could not have happened
-
-
-		-
-
it could not have been happening
-
-
-

Interrogative form

Simple form

V-ing form

-
-
could it happen?
-
-
-		-
-
could it be happening?
-
-
-

Perfect

V-ing perfect

-
-
could it have happened?
-
-
-		-
-
could it have been happening?
-
-
-

Interro-negative form

Simple form

V-ing form

-
-
could it not happen?
-
-
-		-
-
could it not be happening?
-
-
-

Perfect

V-ing perfect

-
-
could it not have happened?
-
-
-		-
-
could it not have been happening?
-
-
-