Expressing "except" and "in addition" with "chule… yiwai"

除了 means both "except" and "besides" — the adverb in the second clause tells you which.

除了 + X (+ 以外)，Subj. + 都 / 也 / 还 ⋯⋯

How it works

With 都, it excludes: 除了他，我们都去过 — everyone except him has been.

With 也 or 还, it includes: 除了中文，他还会说日文 — besides Chinese, he also speaks Japanese.

So the word to watch is not 除了 but what follows in the second half. 以外 is optional throughout.

chú le tā, wǒ men dōu qù guò
除了他，我们都去过。
All of us except him have been.
chú le zhōng wén, tā hái huì shuō rì wén
除了中文，他还会说日文。
Besides Chinese, he also speaks Japanese.
chú le zhōu mò yǐ wài, wǒ měi tiān dōu shàng bān
除了周末以外，我每天都上班。
Apart from weekends, I work every day.