に沿(そ)ってAlong, In accordance with, In line with

When used to mean in line with or in accordance with, にしたがって and に沿って are similar and often interchangeable, as in 規則（にしたがって／に沿って）行動する (act according to the regulations). However, に沿って can also mean along(side), as in 川に沿って歩く (walk alongside the river), while にしたがって cannot.

Both expressions mean in line with or in accordance with. に沿って can be literal or figurative, as in 点線に沿って (along the dotted line) or スケジュールに沿って (in line with the schedule). に則って・に則り is more formal, often implying compliance with official rules or principles, as in 法律に則って (in accordance with the law).

に沿って and に応じて can both suggest doing something in line with a standard, but differ in nuance. に沿って means according to, as in 会社の方針に沿って行動する (act according to company policy). に応じて implies acting in response to or suitable for something, as in 客のニーズに応じてサービスを提供する (provide a service suitable for customers’ needs).

に沿って and に伴って・に伴い both imply corresponding relationships, but with different nuances. に沿って means in line with in literal or figurative contexts, as in 点線に沿って (along the dotted line) or スケジュールに沿って (in line with the schedule). に伴って・に伴い suggests one change occurring along with another, as in 人口減少に伴って (along with the declining population).

Both convey doing something in accordance with something else, but differ in nuance. れる・られる + ままに implies doing something exactly as told or forced, with little choice, as in 指示されるがままにやった (I did it exactly as instructed). に沿って simply means in line with a tangible or figurative standard, as in 点線に沿って (along the dotted line) or スケジュールに沿って (in line with the schedule), without implying lack of control.

While both と並んで and に沿って indicate some kind of coordination, their core meanings differ. と並んで highlights equivalence or joint status, e.g. 'ドラえもんと並んで人気のアニメ' ('an anime as popular as Doraemon'). に沿って means 'in line with' or 'according to', emphasizing adherence to a path, rule, or guideline, e.g. '規則に沿って行動する' ('act in accordance with the rules').