may happen
Verbo regular: happen - happened- happened

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
-
-
it may happen
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-
- 	-
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it may be happening
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-
- 	-
-
it may have happened
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-
- 	-
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it may have been happening
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-
- 	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
-
-
it may not happen
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-
- 	-
-
it may not be happening
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-
- 	-
-
it may not have happened
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-
- 	-
-
it may not have been happening
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-
- 	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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-
may it happen?
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-
- 	-
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may it be happening?
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-
- 	-
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may it have happened?
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-
- 	-
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may it have been happening?
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-
- 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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-
may it not happen?
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-
- 	-
-
may it not be happening?
-
-
- 	-
-
may it not have happened?
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-
- 	-
-
may it not have been happening?
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-
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