“以便”和“以免”
Both open the second clause and give the purpose of what the first clause describes. 以便 introduces the result you want; 以免 the result you want to avoid. Neither can open the sentence, and 以免 is never followed by 不.
结构
做法，以便 + 希望达到的结果 ｜ 做法，以免 + 不希望发生的事
讲解
本文中的中文词语都可以激活，查看词典释义。
The first clause describes what someone does; the second explains why. means “so that, in order to make it easier to”: ， “Please leave your phone number so that we can contact you promptly.” means “so as not to, in case”: ， “Take an extra layer when you go out, so as not to catch cold.”
Both are written-style conjunctions and stand at the head of the second clause. Unlike , they cannot open the sentence: ， is wrong; the action comes first — ，.
already contains the negative idea “avoid”, so what follows it is the unwanted event, stated positively: , . Adding reverses the meaning — would mean “so as not to remember” — the same trap as … in find-the-error questions. is a spoken equivalent of .
The choice between the two is therefore a matter of whether the second clause is something to aim for or something to avoid. makes no sense, because nobody aims to catch a cold.
正确
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.
请留下您的电话号码，以便我们及时和您联系。請留下您的電話號碼，以便我們及時和您聯繫。
Qǐng (third tone, dipping) liúxià (second tone, rising) nín (second tone, rising) de (neutral tone) diànhuà (fourth tone, falling) hàomǎ, (fourth tone, falling) yǐbiàn (third tone, dipping) wǒmen (third tone, dipping) jíshí (second tone, rising) hé (second tone, rising) nín (second tone, rising) liánxì. (second tone, rising)···
Please leave your phone number so that we can contact you promptly.
出门时多带一件衣服，以免着凉。出門時多帶一件衣服，以免著涼。
Chūmén (first tone, high and level) shí (second tone, rising) duō (first tone, high and level) dài (fourth tone, falling) yí (second tone, rising) jiàn (fourth tone, falling) yīfu, (first tone, high and level) yǐmiǎn (third tone, dipping) zháoliáng. (second tone, rising)···
Take an extra layer when you go out, so as not to catch cold.
他把重要的内容都记在本子上，以免忘记。他把重要的內容都記在本子上，以免忘記。
Tā (first tone, high and level) bǎ (third tone, dipping) zhòngyào (fourth tone, falling) de (neutral tone) nèiróng (fourth tone, falling) dōu (first tone, high and level) jì (fourth tone, falling) zài (fourth tone, falling) běnzi (third tone, dipping) shang, (neutral tone) yǐmiǎn (third tone, dipping) wàngjì. (fourth tone, falling)···
He writes everything important in a notebook so that he won’t forget it.
错误 — 常见错误
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.
不太对
Incorrect sentence: 天气冷了，多穿点儿衣服，以便感冒。
正确
Correct sentence: 天气冷了，多穿点儿衣服，以免感冒。
为什么: A cold is something to avoid, so the word is 以免. 以便 introduces what you want to happen.
不太对
Incorrect sentence: 出门前检查一下，以免不忘带钥匙。
正确
Correct sentence: 出门前检查一下，以免忘带钥匙。
为什么: 以免 already means “to avoid”. The event after it is stated positively, without 不.
不太对
Incorrect sentence: 以便大家阅读，他把资料放在了网上。
正确
Correct sentence: 他把资料放在了网上，以便大家阅读。
为什么: 以便 opens the second clause, after the action. Only 为了 can open the sentence.
对比
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.
以免 is one of the words with a negative built in, like 防止, 避免 and 否认. The same counting rule applies: 以免 + 不 makes two negatives and turns the meaning round. 以便 has no negative inside it, so 以便不… is possible when the wanted result is itself negative: 以便不影响别人休息.
病句辨析：否定不当 →小测验
第 1 题 / 3总分: 0
Choose the word for the gap.
开车的时候请注意安全，___ 发生交通事故。