最【zuì】

最 before an adjective makes it a superlative: "most" or "-est". There are no irregular forms: "best" is simply 最好.

Before a noun, 的 links them: 最好的朋友, 最贵的手机. Drop the noun and 的 stays.

最 replaces 很; the two don't stack.

• × 这个最很贵 → 这个最贵

The group goes in front

Whatever the superlative is measured against comes before 最, not after.

• × 这是最大的教室在我们学校 → 这是我们学校最大的教室

最 with a verb

Verbs of liking and wanting take 最 directly, and 最喜欢的 + noun is how you say "favourite".

最好 as advice

In front of a verb, zuì hǎo最好 stops being a superlative and means "you'd better".