hence

Compared meaning: as a result, so (connecting adverb).

比较义项：表示结果或结论的连接副词“因此”（副词）。

• thus

  Thus is formal and literary, often introducing a resulting action, and can directly precede an -ing verb ("thus doubling"), a pattern therefore and hence rarely use in the same way.

  thus 语气正式、偏书面语，常用来引出一个结果性动作，并能直接接现在分词（如 "thus doubling"，因此使……翻倍），这种用法 therefore 和 hence 很少以同样方式使用。

  The factory automated its production line, thus doubling output within a year.

  这家工厂实现了生产线自动化，因此在一年内使产量翻了一倍。

• therefore

  Therefore is the most neutral and common of the three, natural in both formal writing and everyday speech, and always introduces a full clause with its own subject and verb.

  therefore 是三者中最中性、最常用的一个，正式写作和日常口语中都很自然，并且总是引出一个带有主语和谓语的完整分句。

  The flight was overbooked; therefore, several passengers were asked to volunteer.

  这趟航班超额订票了；因此，几名乘客被要求自愿放弃座位。

• hence 本词

  Hence is the most formal and somewhat old-fashioned of the three, and often drops the verb entirely, linking straight to a noun phrase ("hence the delay") rather than a full clause.

  hence 是三者中最正式、略显古旧的一个，常常完全省略动词，直接连接一个名词短语（如 "hence the delay"，因此才有了这次延误），而不是完整的分句。

  The venue flooded overnight, hence the sudden change of location.

  场地一夜之间被水淹了，因此才临时更换了场地。

All three mean 'as a result'. Thus is formal and literary. Therefore is the most neutral, common in formal and casual English. Hence is formal and old-fashioned; it often drops the verb, linking to a noun. Thus can mean 'in this way'; not compared here.

这三个词表示“因此”时意思相近，都用来引出结果或结论，但正式程度和搭配习惯不同：thus 和 hence 更正式、更偏书面语，therefore 是三者中最中性、口语书面都常用的一个；hence 还常常省略动词，直接接名词短语。此处不比较 thus 表示“这样地”（方式）的另一层含义。