1 a single slip may cause everlasting sorrow (idiom)
一成不变
yī chéng bù biàn
1 nothing much changes (idiom); always the same
2 stuck in a rut
一条路走到黑
yī tiáo lù zǒu dào hēi
1 lit. to follow one road until dark (idiom)
2 fig. to stick to one's ways
3 to cling to one's course
一清如水
yī qīng rú shuǐ
1 lit. as clear as water (idiom)
2 fig. (of officials etc) honest and incorruptible
一碗水端平
yī wǎn shuǐ duān píng
1 lit. to hold a bowl of water level (idiom)
2 fig. to be impartial
一语成谶
yī yǔ chéng chèn
1 (idiom) to have one's words turn out to be (tragically) prophetic
一雨成秋
yī yǔ chéng qiū
1 a sudden shower towards the end of summer brings an abrupt arrival of autumn (idiom)
一点水一个泡
yī diǎn shuǐ yī gè pào
1 honest and trustworthy (idiom)
三五成群
sān wǔ chéng qún
1 in groups of three or four (idiom)
三人成虎
sān rén chéng hǔ
1 three men talking makes a tiger (idiom); repeated rumor becomes a fact
三个和尚没水喝
sān gè hé shang méi shuǐ hē
1 lit. three monks have no water to drink (idiom)
2 fig. everybody's business is nobody's business
3 (If there is one monk, he will fetch water for himself. If there are two, they will fetch water together. But if there are three or more, none will take it upon himself to fetch water.)