Conjugação do verbo inglês COULD HAPPEN
Verbo regular: happen - happened - happened
Afirmação
Forma simple
--
it could happen
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Forma com V-ing
--
it could be happening
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Perfeito
--
it could have happened
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Perfeito com V-ing
--
it could have been happening
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Negação
Forma simple
--
it couldn't happen
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Forma com V-ing
--
it couldn't be happening
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Perfeito
--
it couldn't have happened
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Perfeito com V-ing
--
it couldn't have been happening
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Forma interrogativa
Forma simple
--
could it happen?
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Forma com V-ing
--
could it be happening?
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Perfeito
--
could it have happened?
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Perfeito com V-ing
--
could it have been happening?
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Forma interro-Negação
Forma simple
--
couldn't it happen?
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Forma com V-ing
--
couldn't it be happening?
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Perfeito
--
couldn't it have happened?
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Perfeito com V-ing
--
couldn't it have been happening?
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