join in,join…in,take part in和attend的区别

Take part in 表示“参加”某项工作、失业、以积极的活动在这工作和事业中起一份作用。
故参加群众的活动、运动、会议等不宜用join in, 而用take part in。
Did you take part in the meeting yesterday? 你参加昨天的会议了吗？
We often take part in physical labour. 我们经常参加体力劳动。
如part前有active修饰，则须加冠词an。
They all took an active part in the fighting. 他们全都积极地参加了战斗。

Join in 意为“参加（某项）活动”，诸如游戏、唱歌、讨论等，有时间可以跟表示延续性的时间状语。
We shall be glad to join in the discussion. 我们将很高兴这项讨论。
“参加某一群人的某项活动”可用join sb. in。
Will you join me in a drink? 你要不要同我一起喝一杯？
Sit down, why don’t you, Mr Atkins, join us for a while? 爱德肯先生，为什么不坐下同我们玩一会儿？

Join的基本意思是“加入”，是非延续性动词，后接党派、社会团体等名词。
He joined the army two years ago. 他两年前参军了。
He joined the Communist Party when he was twenty. 他20岁时入了党。

Join to 是“把……连接”、“连起来”的意思。
You should never join an electric wire to a water pipe. 你绝不可把电线接到水管上。
South America is joined to North America. 南美洲和北美洲相衔接。

Join up是“参军”、“连起来”的意思，up是副词。
Many of them have joined up.他们很多人都参军了。
We joined up small plots of land and made bigger fields. 我们把小块儿的田地连成了大块儿的田。

Attend意为“出席、参加会议、讲演、上课、音乐会”等。
He has decided to attend the wedding.他已决定参加婚礼。
His father suggested that he should attend a technical school.他父亲建议他去上技校