Chinese particle 吧 (ba) can be used to make suggestions or soften the tone of commands.吧 makes the suggestion sound more tentative and more polite.
Structure
command + 吧
Note that when you have a command with the subject "we," you're basically just saying, "let's (do something)." 吧 makes the suggestion sound more tentative and more polite.
Examples
Zánmen zǒu bɑ.
咱们 走 吧。
咱们 走 吧。
(This is a suggestion)
Let's go.