一周才刚过半，他就累倒了。
By midweek he was too tired to go out.
我的精神集中不起来，大概是太累了吧。
I couldn't concentrate, presumably because I was so tired.
一天结束时，我们很累，但很高兴。
By the end of the day we were tired but happy.
孩子们越来越累，脾气也有些变坏了。
The kids were getting tired and a little cranky.