吧
ba
Suggestions with "ba"
吧 turns an order into a suggestion — "let's" rather than "do this".
Command / Suggestion + 吧
How it works
我们走吧 is "let's go". Without 吧 it's a flat statement or a command; with it, it invites agreement.
It works on requests to a single person too: 你先吃吧 — go ahead and eat. The effect is to make the instruction sound relaxed rather than bossy.
Examples
wǒ men zǒu ba
我们走吧。
Let's go.
wǒ men yì qǐ chī fàn ba
我们一起吃饭吧。
Let's eat together.
nǐ xiān xiū xi ba
你先休息吧。
Go and get some rest.