will happen
Regular verb: happen - happened- happened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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it'll happen
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it'll be happening
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it'll have happened
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it'll have been happening
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Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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it won't happen
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it won't be happening
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it won't have happened
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it won't have been happening
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Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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will it happen?
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will it be happening?
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will it have happened?
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will it have been happening?
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Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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won't it happen?
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won't it be happening?
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won't it have happened?
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won't it have been happening?
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