少不了 / 免不了【shǎobuliǎo / miǎnbuliǎo】

少不了 says something has to be there: you can't do without it, or it's sure to turn up. It takes a noun or a verb phrase.

It can also promise that something will happen, like it or not.

免不了

免不了 says something can't be avoided, and it's usually something unwelcome but normal: mistakes, nerves, arguments. It takes a verb phrase, often with 会 or 要.

The two compare like this: 少不了 is about what must be present, 免不了 about what must be put up with.

难免 is close to 免不了 and a little more formal.

少不了 and 不少

不少 means "quite a lot". 少不了 means "can't be missing". Mixing them changes the sentence completely.

• × 他有少不了朋友 → 他有不少朋友