……，且……: and moreover (written)
【高100】复句 / complex sentences (递进)
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
……，且…… (written) adds a second quality or action to the same subject, like a written 而且 / 并且: “and moreover, what is more”. 且 follows a comma and is usually followed by an adverb (十分, 很, 毫不, 总) before the added predicate: 他办事严谨而认真，且十分负责。
Register: 且 is shorter and drier than 不但……而且…… (hsk3-g20) or 并且 (hsk4-g13); it suits reports, notices and character sketches (这家诊所收费合理，且服务周到). The subject is not repeated and nothing announces what follows: no 不但 in front.
To add a further reason, use 况且 (hsk5-g04); it is not the 且 of 尚且 (hsk6-g02) either. If the second part has a different subject or contrasts with the first, you do not use 且: 而 for a contrast, 而且 for a plain addition.
Examples
这个房间干净，且十分安静。
Zhège fángjiān gānjìng, qiě shífēn ānjìng.This room is clean, and very quiet too.
这篇文章的句子简短，且很有节奏。
Zhè piān wénzhāng de jùzi jiǎnduǎn, qiě hěn yǒu jiézòu.The sentences of this essay are short, and very rhythmic too.
这家诊所收费合理，且服务周到，很受附近居民欢迎。
Zhè jiā zhěnsuǒ shōufèi hélǐ, qiě fúwù zhōudào, hěn shòu fùjìn jūmín huānyíng.This clinic charges reasonable fees and gives attentive service, so it is popular with the neighbourhood.
韩愈批评得很直接，且毫不客气。
Hán Yù pīpíng de hěn zhíjiē, qiě háobù kèqi.Han Yu's criticism is very direct, and he spares no politeness.
他办事严谨而认真，且十分负责，获得了领导的信任。
Tā bàn shì yánjǐn ér rènzhēn, qiě shífēn fùzé, huòdé le lǐngdǎo de xìnrèn.He works rigorously and conscientiously, and is very responsible besides, which has earned him his superiors' trust.
这一条街又脏又乱，且一年四季总免不了有种古怪气味。
Zhè yì tiáo jiē yòu zāng yòu luàn, qiě yì nián sìjì zǒng miǎn bu liǎo yǒu zhǒng gǔguài qìwèi.This street is dirty and untidy, and in every season it cannot avoid a strange smell.
Common mistakes
✗ 他很高，且我很矮。 → ✓ 他很高，而我很矮。 (different subject and a contrast: use 而).
✗ 我今天很累，且很想睡觉。 → ✓ 我今天很累，而且很想睡觉。 (in speech you say 而且; 且 smells of writing).