1. 表示此刻正在进行的某件事、某个动作
We are studying English grammar.
我们正在学文法
Are you listening to me ?
你在听我说话吗？
What are you doing ?
你在做什么啊 ?
2. 表示不久的未来即将要发生的事、动作
Hurry up, the train is leaving in five minutes.
快一点，再过5分钟火车就要开了
Are you coming to the party tomorrow?
明天的派对你要来吗？
I am meeting Sandy tonight.
我今天晚上要和Sandy碰面
3. 表示某段特定时间在进行的事、动作或趋势，可能持续了一个星期、几个月、甚至一年
Mary is writing another book this year.
Mary今年在写另外一本书
Are you still working for the same company?
你还在同一家公司工作吗？
More and more people are becoming vegetarians.
越来越多人吃素
4. 与副词always, forever, constantly 联用，抱怨或强调不断重覆发生的事、动作
James and Annie are always arguing.
James和Annie总是在吵架
He is forever bragging about how much money he earns.
他永远在吹嘘自己赚多少钱
You are constantly complaining about your job.
你总是在抱怨你的工作
