一般来说 / 一般说来【yìbān lái shuō / yìbān shuō lái】

一般来说 frames a statement as the usual case: true as a rule, with exceptions allowed. It normally opens the sentence, followed by a comma.

It can also follow the topic, without the commas.

一般说来 means the same and is a little more written.

一般来说 or 一般

一般 alone, before the verb, says what someone usually does. 一般来说 stands outside the clause and makes a broader claim about how things tend to be.

Only for what usually happens

The phrase describes a pattern. A single event can't be "generally" anything.

• × 一般来说，他昨天来晚了 → 他昨天来晚了
• × 一般来说，我明天去北京 → 我明天去北京

Other phrases built on 来说 – 总的来说 "all in all", 相对来说 "relatively speaking", 对…来说 "for someone" – have their own points.