请
qǐng
Polite requests with "qing"
请 in front of a verb turns it into a polite request.
请 + Verb
How it works
请坐 (please sit), 请进 (please come in), 请等一下 (please wait a moment). It's the closest thing Chinese has to a general politeness marker on commands.
请 can also take a person: 请你告诉我 (please tell me). With a person and no verb it means "to invite" or "to treat": 我请你吃饭 — dinner's on me.
Examples
qǐng zuò
请坐。
Please sit down.
qǐng děng yí xià
请等一下。
Please wait a moment.
jīn tiān wǒ qǐng nǐ chī fàn
今天我请你吃饭。
Dinner's on me today.