1.He started to sing and I joined in. 他開始唱起歌來，然后我也跟著唱起來。
2.You don't have to join in; there are more than enough people on the job already. 人夠多了，您就不用插手了。
3.Now and again he'd join in when we were playing video games. 我們玩電子游戲時，他偶爾會和我們一起玩。
4.I didn't want to join in, but Kenneth insisted. 我不想加入，但是肯尼思非要堅持。
5.I did my best to join in, but the conversation was largely unintelligible. 我努力想插上話，可是大部分談話內容我都聽不懂。