必须

• Pinyin: bì xū
• Hanzi breakdown: 必 (bì) — certainly, must; 须 (xū) — need to, must

Meaning

Must; have to. Expresses strong obligation or necessity, stronger than 要 or 应该.

Used for rules, requirements, or logical necessity. More emphatic than 要 (yào) and 应该 (yīnggāi).

Examples

1. 你必须按时完成作业。 You must finish your homework on time.
2. 去那个国家旅游必须有签证。 You must have a visa to travel to that country.
3. 我们必须早点出发，不然会迟到。 We must leave early, otherwise we will be late.

Usage Guide

Context: rules, requirements, obligations, instructions

Tone: firm, authoritative

Do Say

• 你必须戴口罩进入。(You must wear a mask to enter.)
• 这件事必须今天完成。(This matter must be completed today.)

Don't Say

• Avoid using 必须 for gentle suggestions or polite requests — use 应该 (should) or 最好 (had better) when the tone should be softer.

Origin & History

Classical Chinese compound: 必 (bì, certainly, must) + 须 (xū, need, must). Both characters carry a sense of necessity, making the compound emphatic.

Cultural Context

Generation: All ages

Social background: Universal