1) Here's some boiled water. Have a drink whenever you're thirsty.
渴了请随便喝。
2) Help yourself, please.
请随便。
3) Would you help yourself?
请随便吃。
4) Sit anywhere you like, please.
请随便坐。
5) Please help yourself.
请随便用。
6) Please help yourself to wine.
请随意喝点酒。
参考词条