The Conjugator
English verb conjugation
MUST HAPPEN

Regular verb: happen - happened - happened

Affirmation

Simple form

V-ing form

-
-
it must happen
-
-
-		-
-
it must be happening
-
-
-

Perfect

V-ing perfect

-
-
it must have happened
-
-
-		-
-
it must have been happening
-
-
-

Negation

Simple form

V-ing form

-
-
it mustn't happen
-
-
-		-
-
it mustn't be happening
-
-
-

Perfect

V-ing perfect

-
-
it mustn't have happened
-
-
-		-
-
it mustn't have been happening
-
-
-

Interrogative form

Simple form

V-ing form

-
-
must it happen?
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-
-		-
-
must it be happening?
-
-
-

Perfect

V-ing perfect

-
-
must it have happened?
-
-
-		-
-
must it have been happening?
-
-
-

Interro-negative form

Simple form

V-ing form

-
-
mustn't it happen?
-
-
-		-
-
mustn't it be happening?
-
-
-

Perfect

V-ing perfect

-
-
mustn't it have happened?
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-
-		-
-
mustn't it have been happening?
-
-
-