Grammar · Chapter 38
虽…却/但: the written 'although'
A 虽 X，但 Y · A 虽 X，却 Y
虽 is the written twin of 虽然; in the second half it does not take 但是 but the shorter 但 or 却: 他虽年轻，却已经有了丰富的经验. Nobody speaks this way — in conversation it's 虽然…但是. The typical mistake is writing 虽…但是 back to back: the chain is too heavy, written Chinese trims it to 虽…但.
Examples
- 这件衣服虽旧，但洗得很干净。 Zhè jiàn yīfu suī jiù, dàn xǐ de hěn gānjìng. Old as the clothes are, they come out of the wash spotlessly clean.
- 他虽年轻，却已经有了丰富的经验。 Tā suī niánqīng, què yǐjīng yǒu le fēngfù de jīngyàn. Though he is young, he already has plenty of experience.
- 路虽远，他每天都走。 Lù suī yuǎn, tā měitiān dōu zǒu. Far as the road is, he walks it every day.