-대 means like 'It is said that -', so if someone said ''그 남자가 너 좋대 or 좋아한대" means "He says that he likes you" or "Someone says that he likes you. In other words, -대 is used when you say something you heard from others or read on the book or somewhere. It means you get the information indirectly. Also, -대 or -래 is abbreviation of -다고 해 or -라고 해 ex) "톰이 너 보고싶대" -> "톰이 너 보고싶다고 해" - Tom said he miss you "내일 비온대" -> "내일 비온다고 해(신문에서 or 뉴스에서)" - News says it will be rainy tomorrow "톰이 너 오래" -> "톰이 너 오라고 했어" - Tom said to you to come