Cannot help: 不禁 and 不由得
Both describe a reaction the subject could not hold back — laughing, crying, remembering, feeling. They stand after the subject and before a verb of emotion or perception, and despite the 不 they are not negatives.
Structure
（情境），主语 + 不禁／不由得 + 动词（笑、哭、想起、感到……）
Explanation
Chinese words in this text can be activated to show a dictionary gloss.
and mean that something in the situation set off a reaction the person did not choose: ， “Seeing the old photograph, she couldn’t help thinking of her childhood.” ，. The first clause usually names the trigger.
What follows is an involuntary verb: , , , , , , . A deliberate action does not fit — is odd, because buying a ticket is chosen — and that is the error to watch for. is an adverb, so in careful writing it follows the subject: .
Despite the inside them, neither word is a negative. The verb after them is positive, and adding another negation reverses the meaning: is wrong for . This is a favourite trap, because learners read as “do not”.
The two words are close to interchangeable. is more written; is a little more spoken and is often followed by or when the feeling is mild: ，.
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.
看到这张老照片，她不禁想起了小时候。看到這張老照片，她不禁想起了小時候。
Kàndào (fourth tone, falling) zhè (fourth tone, falling) zhāng (first tone, high and level) lǎo (third tone, dipping) zhàopiàn, (fourth tone, falling) tā (first tone, high and level) bùjīn (fourth tone, falling) xiǎngqǐ (third tone, dipping) le (neutral tone) xiǎoshíhou. (third tone, dipping)···
Seeing the old photograph, she couldn’t help thinking of her childhood.
听到这个好消息，大家都不由得笑了起来。聽到這個好消息，大家都不由得笑了起來。
Tīngdào (first tone, high and level) zhège (fourth tone, falling) hǎo (third tone, dipping) xiāoxi, (first tone, high and level) dàjiā (fourth tone, falling) dōu (first tone, high and level) bùyóude (fourth tone, falling) xiào (fourth tone, falling) le (neutral tone) qǐlái. (third tone, dipping)···
Hearing the good news, everyone burst out laughing.
一个人走在这条安静的小路上，我不由得有点儿害怕。一個人走在這條安靜的小路上，我不由得有點兒害怕。
Yí (second tone, rising) ge (neutral tone) rén (second tone, rising) zǒu (third tone, dipping) zài (fourth tone, falling) zhè (fourth tone, falling) tiáo (second tone, rising) ānjìng (first tone, high and level) de (neutral tone) xiǎo (third tone, dipping) lù (fourth tone, falling) shang, (neutral tone) wǒ (third tone, dipping) bùyóude (fourth tone, falling) yǒudiǎnr (third tone, dipping) hàipà. (fourth tone, falling)···
Walking alone down this quiet lane, I couldn’t help feeling a little afraid.
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: 离开家乡十年了，我不禁不想起了小时候的朋友。
Correct
Correct sentence: 离开家乡十年了，我不禁想起了小时候的朋友。
Why: 不禁 is not a negative. The verb after it is positive; an extra 不 reverses the meaning.
Not quite
Incorrect sentence: 看到这么便宜的衣服，他不禁买了两件。
Correct
Correct sentence: 看到这么便宜的衣服，他马上买了两件。
Why: Buying is a deliberate act. 不禁 goes with involuntary reactions such as laughing, crying or feeling.
Not quite
Incorrect sentence: 听了他的话，不禁大家都笑了。
Correct
Correct sentence: 听了他的话，大家都不禁笑了。
Why: 不禁 is an adverb and follows the subject (and 都).
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.
Find-the-error questions use both points the same way: they count negatives. In 防止…不 a hidden negative is doubled; in 不禁不 a word that only looks negative is treated as one. In both cases the fix is to delete the extra 不.
Finding the error: one negative too many →Mini quiz
Question 1 / 3Total score: 0
Is this sentence correct?
看完这个感动人的故事，很多人都不禁哭了。