So much that: 以至（于） and 以致
Both open the second clause and introduce a result. 以至（于） says a situation went so far that it reached this point; 以致 says a cause led to an outcome nobody wanted, and is used almost only for bad results.
Structure
甲（程度很深），以至（于）+ 结果 ｜ 甲（原因），以致 + 不好的结果
Explanation
Chinese words in this text can be activated to show a dictionary gloss.
Both words belong to written Chinese and both stand at the head of the second clause, before its subject if it has one. They differ in what they emphasise.
(often ) is about degree. The first clause describes something intense, frequently with , or , and the second says how far it went: ， “He was so absorbed in his work that he forgot to have lunch.” The result can be neutral or even pleasant: ，.
is about consequence, and the consequence is unwelcome: ， “He never paid attention to rest, and in the end he fell ill.” The first clause is usually a cause someone could have avoided. Using for a good result — ， — is a standard error; the right word there is simply or .
Two positional points. Neither word can open the whole sentence: the cause comes first. And because each is a conjunction, it stands before the subject of its clause: ，, or — but not ….
Correct
Say each one out loud before moving on. The audio is a reference pronunciation, not a model to imitate exactly — match the tone contour, not the voice.
他工作太专心了，以至于忘了吃午饭。他工作太專心了，以至於忘了吃午飯。
Tā (first tone, high and level) gōngzuò (first tone, high and level) tài (fourth tone, falling) zhuānxīn (first tone, high and level) le, (neutral tone) yǐzhìyú (third tone, dipping) wàng (fourth tone, falling) le (neutral tone) chī (first tone, high and level) wǔfàn. (third tone, dipping)···
He was so absorbed in his work that he forgot to have lunch.
他平时不注意休息，以致病倒了。他平時不注意休息，以致病倒了。
Tā (first tone, high and level) píngshí (second tone, rising) bú (second tone, rising) zhùyì (fourth tone, falling) xiūxi, (first tone, high and level) yǐzhì (third tone, dipping) bìng (fourth tone, falling) dǎo (third tone, dipping) le. (neutral tone)···
He never paid attention to rest, and in the end he fell ill.
这个问题非常复杂，以至于专家们的看法也不一样。這個問題非常複雜，以至於專家們的看法也不一樣。
Zhège (fourth tone, falling) wèntí (fourth tone, falling) fēicháng (first tone, high and level) fùzá, (fourth tone, falling) yǐzhìyú (third tone, dipping) zhuānjiāmen (first tone, high and level) de (neutral tone) kànfǎ (fourth tone, falling) yě (third tone, dipping) bù (fourth tone, falling) yíyàng. (second tone, rising)···
The problem is so complicated that even the experts disagree.
Incorrect — Common mistakes
These sentences are wrong. They are printed here on purpose, each one paired with the repair and the reason, because the error you can recognise is the error you stop making.
Not quite
Incorrect sentence: 他认真复习，以致考得很好。
Correct
Correct sentence: 他认真复习，所以考得很好。
Why: 以致 introduces unwanted outcomes. For a good result, use 所以 or 因此.
Not quite
Incorrect sentence: 他太累了，他以至于在车上睡着了。
Correct
Correct sentence: 他太累了，以至于在车上睡着了。
Why: 以至于 is a conjunction and opens its clause. If the clause keeps a subject, it follows: 以至于他在车上睡着了.
Not quite
Incorrect sentence: 以至于很多人都感冒了，天气突然变冷。
Correct
Correct sentence: 天气突然变冷，以至于很多人都感冒了。
Why: The cause comes first and the 以至于 clause second; the pattern cannot be turned round.
Compared with
Most errors with this pattern are not errors about this pattern — they are a neighbouring pattern arriving at the wrong moment. Read these side by side.
所以 is neutral: it states that one thing follows from another, good or bad. 以至于 adds “to such a degree”, and 以致 adds “and, unfortunately, this was the consequence”. When in doubt about a good outcome, 所以 is always safe; 以致 is not.
Cause and result: 因为…所以… →Mini quiz
Question 1 / 3Total score: 0
Choose the word for the gap.
他平时不注意饮食，___ 得了胃病。