Here the word "we" refers to James and the elders. (See: [Acts 21:18](./17.md) and [[rc://en/ta/man/translate/figs-exclusive]])
The word "They" refers to the Jewish believers in Jerusalem who wanted to teach Jewish believers that they could still follow the laws of Moses. (See: [Acts 21:20-21](./20.md))
The words "them," "their," and the first "they" refer to the four men who made a vow. The second words "they" and "They" refer to the Jewish believers in Jerusalem who wanted to teach Jewish believers that they could still follow the laws of Moses.