| 一举两得 | yī jǔ liǎng dé | one move, two gains (idiom); two birds with one stone |
| 一个劲儿 | yī gè jìnr | erhua variant of 一个劲, persistently; continuing |
| 一清二楚 | yī qīng èr chǔ | to be very clear about sth (idiom) |
| 专一 | zhuān yī | single-minded; concentrated |
| 一席话 | yī xí huà | what is said during a conversation; an utterance |
| 一眨眼 | yī zhǎ yǎn | in a wink |
| 一败涂地 | yī bài tú dì | failed and wiped over the floor (idiom); to fail utterly; a crushing defeat; beaten and in a hopeless position |
| 一览 | yī lǎn | an overview; at a glance |
| 一元论 | yī yuán lùn | monism, belief that the universe is made of a single substance |
| 不可一世 | bù kě yī shì | consider oneself unexcelled in the world; be insufferably arrogant |
| 一如既往 | yī rú jì wǎng | just as in the past (idiom); as before; continuing as always |
| 一意孤行 | yī yì gū xíng | isolated and stubborn; obstinately clinging to one's course; willful; one's own way; dogmatic |
| 一清早 | yī qīng zǎo | early in the morning |
| 一无所知 | yī wú suǒ zhī | not knowing anything at all (idiom); completely ignorant; without an inkling |
| 奄奄一息 | yān yān yī xī | dying; at one's last gasp |
| 摇身一变 | yáo shēn yī biàn | to change shape in a single shake; fig. to take on a new lease of life |
| 一去不复返 | yī qù bù fù fǎn | gone forever |
| 一笔勾销 | yī bǐ gōu xiāo | to write off at one stroke |
| 一网打尽 | yī wǎng dǎ jìn | to catch everything in one net (idiom); to eliminate at one stroke; to solve the problem at one fell swoop |
| 大一统 | dà yī tǒng | unification (of the nation); large scale unification |
| 孤注一掷 | gū zhù yī zhì | to stake all on one throw |
| 万众一心 | wàn zhòng yī xīn | millions of people all of one mind (idiom); the people united |
| 一概而论 | yī gài ér lùn | (saying) lump different matters together |
| 一把手 | yī bǎ shǒu | working hand; member of a work team; participant |
| 一瞥 | yī piē | glance; glimpse |
| 一丝一毫 | yī sī yī háo | one thread, one hair (idiom); a tiny bit; an iota |
| 一脉相承 | yī mài xiāng chéng | traceable to the same stock (idiom); of a common origin (of trends, ideas etc) |
| 不一而足 | bù yī ér zú | by no means an isolated case; numerous |
| 始终如一 | shǐ zhōng rú yī | unswerving from start to finish (idiom) |
| 万无一失 | wàn wú yī shī | surefire; absolutely safe (idiom) |
| 言行一致 | yán xíng yī zhì | word and actions coincide (idiom); to live up to one's word; to match words with deeds; Practice what you preach. |
| 一五一十 | yī wǔ yī shí | lit. count by fives and tens (idiom); to narrate systematically and in full detail |
| 一口咬定 | yī kǒu yǎo dìng | to arbitrarily assert; to allege; to stick to one's statement; to cling to one's view |
| 一场空 | yī chǎng kōng | all one's hopes and efforts come to nothing; futile |
| 一窍不通 | yī qiào bù tōng | I don't understand a word (idiom); all Greek to me |
| 一筹莫展 | yī chóu mò zhǎn | to be unable to find a solution; to be at wits' end |
| 一蹶不振 | yī jué bù zhèn | one stumble, unable to rise (idiom); a setback leading to total collapse; ruined at a stroke; unable to recover after a minor hitch |
| 合而为一 | hé ér wéi yī | to merge together (idiom); to unify disparate elements into one whole |
| 告一段落 | gào yī duàn luò | to come to the end of a phase (idiom) |
| 清一色 | qīng yī sè | monotone; only one ingredient; (mahjong) all in the same suit |
| 盛极一时 | shèng jí yī shí | all the rage for a time; grand fashion for a limited time |
| 灵机一动 | líng jī yī dòng | a bright idea suddenly occurs (idiom); to hit upon an inspiration; to be struck by a brainwave |
| 独一无二 | dú yī wú èr | unique and unmatched (idiom); unrivalled; nothing compares with it |
| 一会儿…一会儿… | yī huìr yī huìr | one moment... the next... |
| 一…也… | yī yě | only... |
| 一…就… | yī jiù | as soon as... |
| 一一 | yī yī | one by one; one after another |
| 一下子 | yī xià zi | in a short while; all at once; all of a sudden |
| 一半 | yī bàn | half |
| 一技之长 | yī jì zhī cháng | (saying) skill or proficiency |