有的；例如 Mr Smith must be at home now.He can't be from England (表状态)
Mr Smith can't be having lunch now.It's only 10:30 (对现在动作的推测)
Mr Smith couldn't have gone to the concert last night.(对过去动作的推测)
有的；例如 Mr Smith must be at home now.He can't be from England (表状态)
Mr Smith can't be having lunch now.It's only 10:30 (对现在动作的推测)
Mr Smith couldn't have gone to the concert last night.(对过去动作的推测)