The term 'แค่ (khâe)' is used in Thai to express a limiting condition or a minimal action, similar to the English 'just', 'only' or 'merely'. It's usually placed before verbs and adjectives to highlight the minimal extent of the action or condition represented. It's quite versatile and can be used in a variety of sentence structures, specifically when you want to underscore that something is not as much or as extreme as it could be.