答案： 整点钟用介词at,例如at eight o'clock .具体某一天用介词on.例如on Sunday.in the morning ,in the afternoon ,in the evening是固定搭配.in two weeks. 两个星期后.用于将来时态. 【Me YC真诚为你解答此题...具体到某一天用介词on;on the evening of Aug.23,2009.具体到某年的某天呢的某时也是用介词on啊.例如on the evening of Aug.23,2009.只具体到某年用on？某月用什么具体到某年某月某人是用on的，你整理一下思绪免得越搞越晕亲I was born in 1998I was born ? 1998,July用on啊，具体到某年某月用介词on.还不明白啊亲明白了，谢谢只说到某一年是用介词in的