Modal Verbs Can/Could in the Meaning of Possibility and Surprise Could they have closed the laboratory without bringing their research to the completion? He could not have gone to Europe alone, he almost doesn't speak English. Could he have suspected my husband in committing the crime? He has never had problems with the law. Could he have failed his English exam again after making so many efforts over the last month? He could not have provided such an unreliable information to you. You must have misunderstood something. He cannot be waiting for us for long, so we have to hurry. He couldn't have missed the flight yesterday because I was along with him until the boarding starts. Could anybody have supposed him turned out to be a thief? He always seemed such a loyal man.