it won't be very long before + 句子（謂語(yǔ)動(dòng)詞用一般現(xiàn)在時(shí)）如：It won't be long before I return to Beijing翻譯：我很快就要回北京了It will be two weeks before she comes here.翻譯：過(guò)兩周她就來(lái)了.How lo...此否定結(jié)構(gòu)能否把before 換為until?你好。不可以，因?yàn)樗鼈冎g不存在互換關(guān)系。 It won't be long before I return to Beijing------It won't be long until I return to Beijing.(是錯(cuò)句)，但這一句是對(duì)的：I won't return to Beijing until Monday / -- ---until next week./ -- -- - until five days from today.