往后走。

You use it when you want someone to clear space. Or when you are giving directions to a hidden spot. Just say the three words clearly. You can add a 请 (please) at the start to be polite. Without 请, it sounds like a command. Use it when you are physically pointing or gesturing.

Use it on a packed subway to find more room. Use it when showing a friend a cool shop down an alley. It works well when you are leading a group. If you are a waiter, use it to guide guests to a back table. It is perfect for physical navigation. It feels natural and helpful in busy cities.

Don't use it to mean 'return to the past.' It is for physical movement only. Don't use it if you mean 'go back to where you came from.' For that, use 回去. If you use it with a boss, add 请. Otherwise, you might sound like you are bossing them around. Avoid using it in a deep emotional argument about 'moving on.'

In China, crowded public transport is a daily reality. You will hear bus conductors shouting this constantly. It represents the 'flow' of people in high-density urban life. There is a collective understanding that moving back helps everyone. It is a phrase of efficiency. It reflects the pragmatic nature of Chinese social navigation.

You might hear 往后退 which means 'step back' for safety. Or 往里走 which means 'move further inside.' 往后边走 adds a noun-suffix but means the same thing. In Beijing, people might add an 'r' sound: 往后走儿. All of these serve the same goal: making space.