In Thai, 'มั้ย (mái)' is a conversational particle that changes statements into questions. Think of it as a casual, colloquial equivalent to the English 'right?' or 'isn't it?'. This informal question marker is usually placed at the end of the sentence. In a more formal context, however, 'ไหม (mái)' would be used instead. Using 'มั้ย (mái)' in your everyday conversation can make you sound more like a native Thai speaker.