Ⅰ. join 可用来表示加入某个政党、团体、组织等, 指成为其中的成员。如:
① My uncle joined the Party in 1989.
② We are going for a swim .Will you come and join us. 我们要去游泳,你和我们一起去好吗?
Ⅱ. join in 表“加入、参与”某种活动,后接名词或动词的ing 形式,表“参加某人的活动”可以说:join sb. in (doing) sth. 如:
① He joined them in the work.他同他们一起工作。
② Will you join us in playing basketball? 你跟我们一起打篮球好吗?
Ⅲ. take part in 指“参加”会议、考试、竞赛或群众性活动,重在说明句子主语参加该项活动并在其中发挥作用。如:
① The teacher took part in our discussion yesterday. 昨天老师参加了我们的讨论。
② When will you take part in the meeting? 你将在什么时候参加会议?
:join in 后面可以不跟宾语。而take part in 后面必须跟宾语。如:
Let me join in. 让我参加吧。