沿着 / 沿: along
【六14】介词 / prepositions (方向、路径)
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
沿(着) + a line + verb: you move, or things stretch out, along a river, a road or a coast. The whole phrase goes before the verb: 沿着河边散步, 沿着这条路一直走. A place can be the subject too: 沿着海边修了一条自行车道 (a cycle path runs along the seafront). It needs a real or figurative line (河, 路, 海岸, 街), never a bare point or a direction.
Do not mix it up with 往 (hsk2-g45), which gives a direction (往北走, "go north"), or with 从 (hsk1-g35), which gives a starting point. 沿着 follows the line itself, and all three combine: 从这儿沿着河往东走.
Written Chinese uses 沿 alone in compounds: 沿海 (coastal), 沿途 (along the way), 沿线 (along the line), 沿岸 (the banks). Figuratively you follow a line of thought: 沿着这个方向继续研究. Neutral register, common in speech and in writing.
Examples
沿着这条路一直走，到红绿灯往右拐。
Yánzhe zhè tiáo lù yìzhí zǒu, dào hónglǜdēng wǎng yòu guǎi.Follow this road straight on and turn right at the traffic lights.
我们沿着河边散步，一边走一边聊天。
Wǒmen yánzhe hébiān sànbù, yìbiān zǒu yìbiān liáotiān.We stroll along the river, chatting as we walk.
从火车站出来，沿着大街往北走十分钟就到了。
Cóng huǒchēzhàn chūlái, yánzhe dàjiē wǎng běi zǒu shí fēnzhōng jiù dào le.Come out of the station and follow the main street north: ten minutes and you're there.
沿着海边修了一条很长的自行车道，周末骑车的人很多。
Yánzhe hǎibiān xiū le yì tiáo hěn cháng de zìxíngchē dào, zhōumò qí chē de rén hěn duō.A long cycle path has been built along the seafront, and plenty of people ride on it at the weekend.
沿海地区的夏天又热又潮湿，冬天却不太冷。
Yánhǎi dìqū de xiàtiān yòu rè yòu cháoshī, dōngtiān què bú tài lěng.In the coastal areas the summers are hot and humid, but the winters are not very cold.
我们应该沿着这个方向继续研究下去。
Wǒmen yīnggāi yánzhe zhège fāngxiàng jìxù yánjiū xiàqu.We should carry on our research along these lines.
Common mistakes
✗ 我们走沿着河。 → ✓ 我们沿着河走 (the 沿着 + line phrase goes before the verb).
✗ 沿着北走 → ✓ 往北走 (沿着 needs a line such as a road or a river, not a bare direction).