used to say that you think that something is probably true 很可能;大概;想必是 Presumably this is where the accident happened. 这大概就是事故现场。 You'll be taking the car, presumably? 想必您是要买这辆汽车了? I couldn't concentrate, presumably because I was so tired. 我的精神集中不起来,大概是太累了吧。 Presumably you’ll be leaving the children at home. 你应该会把孩子们留在家里吧。