'never' is used as an exclamation that expresses disbelief or disapproval.
'never' is usually used to express a strong negative sentiment, such as disbelief, disbelief at the absurdity of something, or distaste. It can be used as both an interjection and an emphatic adverb.
1. 'I can’t believe I said that - never!'
2. 'He said he would never do it, and now he’s changed his mind!'
3. 'You’d never guess what happened to her!'
be careful when using 'never' as it can come off as overly negative or dismissive. It is better to use a softer word, such as 'rarely' or 'seldom,' if you do not wish to be too extreme in your expression.