所以

所以

1. therefore; so; consequently

   明天要考試了，所以我今天只能留在家裡複習功課。 [MSC, trad.]
   明天要考试了，所以我今天只能留在家里复习功课。 [MSC, simp.]

   Míngtiān yào kǎoshì le, suǒyǐ wǒ jīntiān zhǐ néng liú zài jiālǐ fùxí gōngkè. [Pinyin]

   I have a test tomorrow, so I have to stay at home today and review my homework.

   他是南方人，所以一張口說話就帶有南方口音。 [MSC, trad.]
   他是南方人，所以一张口说话就带有南方口音。 [MSC, simp.]

   Tā shì nánfāngrén, suǒyǐ yī zhāngkǒu shuōhuà jiù dàiyǒu nánfāng kǒuyīn. [Pinyin]

   He is from the South, so when he opens his mouth to speak, you can hear his Southern accent.

   今天是你奶奶的生辰，所以你非來不可。 [MSC, trad.]
   今天是你奶奶的生辰，所以你非来不可。 [MSC, simp.]

   Jīntiān shì nǐ nǎinai de shēngchén, suǒyǐ nǐ fēi lái bùkě. [Pinyin]

   It's your grandma's birthday today, so you've got to attend.

2. Used in the first part of a sentence to indicate a reason that will be explained in the second part of the sentence.

   我所以要反對這個計畫，是因為我覺得其中有不少疏漏。 [MSC, trad.]
   我所以要反对这个计画，是因为我觉得其中有不少疏漏。 [MSC, simp.]

   Wǒ suǒyǐ yào fǎnduì zhège jìhuà, shì yīnwèi wǒ juéde qízhōng yǒu bùshào shūlòu. [Pinyin]

   My reason for opposing this plan, is because I feel that there are quite a few holes in it.

• (therefore):

所以

1. (literary) the means (literally, "what one uses") by which; how

   • 君子不以其所以養人者害人。 [Classical Chinese, trad.]
     君子不以其所以养人者害人。 [Classical Chinese, simp.]

     From: Mencius, c. 4^th century BCE, translated based on James Legge's version

     Jūnzǐ bù yǐ qí suǒyǐ yǎngrén zhě hàirén. [Pinyin]

     [A] ruler does not injure his people with that wherewith he nourishes them.

   • 夫人所以貴者，乃此男也。 [Classical Chinese, trad.]
     夫人所以贵者，乃此男也。 [Classical Chinese, simp.]

     From: The Records of the Grand Historian, by Sima Qian, c. 91 BCE

     Fūrén suǒyǐ guì zhě, nǎi cǐ nán yě. [Pinyin]

     Madame, the means through which you attain your destined status will be none but this son of yours.

2. (literary) the manner in which; how

   • 不患無位，患所以立。 [Classical Chinese, trad.]
     不患无位，患所以立。 [Classical Chinese, simp.]

     From: The Analects of Confucius, c. 475 – 221 BCE, translated based on James Legge's version

     Bù huàn wú wèi, huàn suǒyǐ lì. [Pinyin]

     I am not concerned that I have no place; I am concerned how I may fit myself for one.

3. (literary) the reason why; why

   所以然  ―  suǒyǐrán  ―  the reason why it is what it is

   之所以  ―  zhīsuǒyǐ  ―  the reason why (chiefly used between subject and predicate)

   • 斯民也，三代之所以直道而行也。 [Classical Chinese, trad. and simp.]

     From: The Analects of Confucius, c. 475 – 221 BCE, translated based on James Legge's version

     Sī mín yě, sāndài zhīsuǒyǐ zhídào ér xíng yě. [Pinyin]

     This people supplied the ground why the three dynasties pursued the path of straightforwardness.

   • 所以不報謝者，以為小禮無所用。 [Classical Chinese, trad.]
     所以不报谢者，以为小礼无所用。 [Classical Chinese, simp.]

     From: The Records of the Grand Historian, by Sima Qian, c. 91 BCE

     Suǒyǐ bù bàoxiè zhě, yǐwéi xiǎo lǐ wú suǒyòng. [Pinyin]

     The reason why I have not sought to repay your favour in gratitude is that I do not believe such petty courtesy is of any use to you.

所以

1. (literary) proper behaviour; manners

   忘乎所以  ―  wànghūsuǒyǐ  ―  to lose self-control (literally, "to forget how one should conduct oneself")

• 蔡俊明 [Cai Junming], editor (1991), “所以 so˥˧꜔꜒ i~˥˧꜕꜖”, in 潮州方言詞滙／潮州方言词滙 (Cháozhōu fāngyán cíhuì), 香港 (Xiānggǎng) [Hong Kong]: 香港中文大學／香港中文大学 [The Chinese University of Hong Kong]

Shift from ゆえになり (yue ni nari) → ゆえんなり (yue n nari) → ゆえん (yue-n). See 故 (yue).[1][2][3] The kanji are jukujikun (熟字訓).

• (Tokyo) ゆえん [yùéń] (Heiban – [0])[3]
• IPA^(key): [jɯ̟ᵝẽ̞ɴ]

所以(ゆえん) • (yuen) ^{←ゆゑん (ywen)?}

1. reason, grounds