然后【ránhòu】

然后 starts the next step in a sequence: one thing happens, then another. It goes at the start of its clause and works for plans, instructions and past events alike.

先…然后, "first … then", has its own point.

然后 or 后来

后来 is "later on, afterwards" in a story about the past, usually after a gap in time. 然后 is the next step, past or future. A plan or an instruction only takes 然后.

• × 我们先吃饭，后来去看电影 → 我们先吃饭，然后去看电影

然后 or 以后

以后 goes after an event or a stretch of time: 下课以后, "after class"; 三年以后, "three years later". 然后 stands on its own at the start of a clause and takes nothing in front of it.

• × 下课然后，我们去打球 → 下课以后，我们去打球

In speech, 然后 also strings a story together much like English "and then … and then …", sometimes as a filler while the speaker thinks.