"加入" 的英文是 "join"。
"Join" 是英语中的动词，表示加入或参加某些事情。它来自古英语中的 "giogian"，意思是 "加入"或 "参与"。
例句:
I want to join the club. (我想加入俱乐部。)
Can I join you for dinner? (我能和你一起吃晚饭吗？)
She decided to join the army. (她决定参军。)
He joined the company last month. (他上个月加入了这家公司。)
They are joining forces to fight the enemy. (他们联合起来对抗敌人。)