HSK 7–9 grammar · pattern
别提（有）多X了
别提（有）多X了 — you can't imagine how X
Pattern
+ +
( ) can be left out · other words may come before, between and after
How it works
别提有多…了 is an exclamation of extreme degree: literally "don't even mention how X it was". Despite the negative wording it is emphatic praise or complaint, and the adjective is usually about feeling.
Examples
他别提有多高兴了。
Tā biétí yǒu duō gāoxìng le.
You can't imagine how delighted he was.
那天别提多冷了。
Nà tiān biétí duō lěng le.
You wouldn't believe how cold it was that day.
Related
See it in a story
In the app, 别提（有）多X了 is underlined wherever it appears in the stories you read, and practised with sentences from them. Free.