Eating and drinking

吃饭 (chī fàn) is to eat a meal. Literally it is to eat rice, and it means having eaten anything: a sandwich, a steak, nothing resembling rice at all.

The phrase is so basic that 你吃饭了吗 - have you eaten - functions as a greeting in Chinese roughly the way how are you does in English, and expects about as much detail in reply.

Why the object is attached

Mandarin verbs frequently come with a default object welded on. 吃饭 to eat, 说话 to speak, 睡觉 to sleep, 喝酒 (hē jiǔ) to drink alcohol.

The reason is rhythmic as much as grammatical: Mandarin strongly prefers two-syllable words, and a bare one-syllable verb often sounds unfinished. 吃 on its own is fine when a real object follows - 吃鱼, eat fish - but standing alone it wants a partner.

This also means the object can be split off and replaced, which is how 吃了三碗饭 works: the number and measure word slot in between.

酒 is broader than you think

酒 (jiǔ) is alcohol generally, not specifically wine or spirits. 啤酒 is beer, 白酒 is the strong clear spirit, 葡萄酒 is wine. The bare 酒 covers all of them.

酒店 (jiǔ diàn) is not a pub. It is a hotel, and a fairly smart one. The 店 is a shop or establishment, and the compound settled on the meaning of a hotel with a restaurant long enough ago that the alcohol is incidental.

干杯

干杯 (gān bēi) is cheers, and it means dry the glass. It is not a polite noise, it is an instruction, and in formal or northern settings it is meant literally.

If you would rather not empty the glass, 随意 (suí yì) means as you please and is the accepted way out.

味道

味道 (wèi dào) is taste or flavour, and also a smell. Mandarin is comfortable with one word covering both senses, in the same way English taste covers flavour and judgement.