Namely / even up to (乃 / 乃至)

Structure A + 乃(是) + B (emphatic copula) ／ … + 乃至(于) + extreme case

乃 (nǎi) is a Classical Chinese word still alive in cultured language, with two uses. (1) As an emphatic COPULA, it means "is precisely / is none other than": 失败乃成功之母 = "failure is precisely the mother of success"; 乃是 reinforces that "is" with gravity. (2) 乃至 and its variant 乃至于 mean "and even, up to", marking an ESCALATION: after listing something, a larger or extreme case is added, 全国乃至全世界 = "the whole country and even the entire world". It belongs to literary and essayistic register; in speech one would say 是 or 甚至.

Examples

失shī败bài乃nǎi成chéng功gōng之zhī母mǔ。
Failure is precisely the mother of success.
诚chéng信xìn乃nǎi是shì立lì业yè之zhī本běn。
Integrity is none other than the foundation of any enterprise.
这zhè项xiàng技jì术shù影yǐng响xiǎng全quán国guó乃nǎi至zhì全quán世shì界jiè。
This technology affects the whole country and even the entire world.
此cǐ举jǔ关guān乎hū个gè人rén乃nǎi至zhì于yú整zhěng个gè行háng业yè的de未wèi来lái。
This move concerns the individual and even the future of the whole industry.

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