1、作副詞

①大約,左右.如：There are about 30 students on the playground.操場上大約有30個學生.

②將要,將近.如：I’m about ready.我快準備好了.

③到處,各處.如：The children are running about.孩子們到處亂跑.(表示動向)People are sitting about on the grass.人們在草地的各處坐著.(強調位置)

2、作介詞

①在……到處；在……各處.如：He is walking about the town.他在城鎮到處走.

②關于；對于；有關.如：I am going to read a book about that big city.我要讀一本關于那個大城市的書.

3、固定搭配

①be about to do sth.如：We are about to start.我們即將動身.

②what/how about...……怎么樣?(用于詢問信息或征求意見)如：How about going to Canada for our holidays?咱們去加拿大度假,好嗎?