warn/wɔrn; wɔːn/v [T]1 to tell someone that something bad or dangerous may happen, so that they can avoid it or prevent it 警告﹔提醒: We tried to warn her, but she wouldn’t listen. 我们尽力提醒她﹐但她不愿听。warn sb (that) We warned them that there was a bull in the field. 我们提醒他们﹐田里有一头公牛。warn sb about/of sth Travellers are being warned about the danger of HIV infection. 提醒旅行者要注意预防艾滋病感染。warn sb to do sth We warned them to be careful. 我们提醒他们要小心。COMMUNICATION 交际用法warn someone 警告某人be careful 小心﹐注意: Be careful on the ice. 走在冰上要小心。look out/watch out 小心﹐当心: Look out! There's a car coming. 当心!有车来了。mind 小心﹐当心: Mind the step. 小心台阶。beware of sth written 【书面】谨防某事物: Beware of the dog. 小心有狗。2 to advise someone not to do something because it may have dangerous or unpleasant results〔因可能有危险或产生不良后果而〕告诫〔某人不要做某事〕: warn sb against sth He warned her against such a risky investment. 他告诫过她不要进行风险那么大的投资。warn sb not to do sth I warned her not to walk home alone. 我告诫过她不要一个人走回家。3 to tell someone about something before it happens so that they are not worried or surprised by it 预先通知〔某人以免担忧或惊讶〕: warn sb (that) Can you warn your mother that you’ll be back late? 你能提前告诉你妈妈你会晚归吗?