(一) 正误辨析
1、［误］ We got to the top of the mountain in daybreak.
［正］ We got to the top of the mountain at day break.
［析］ at用于具体时刻之前，如：sunrise, midday, noon, sunset, midnight, night。
2、［误］ Dont sleep at daytime
［正］ Dont sleep in daytime.
［析］ in 要用于较长的一段时间之内，如：in the morning / afternoon, 或 in the week / month / year. 或 in spring / supper /autumn / winter等等。
3、［误］ We visited the old man in Sunday afternoon.
［正］ We visited the old man on Sunday afternoon.
［析］ in the morning, in the afternoon 如果在这两个短语中加入任何修饰词其前面的介词都要改为on, 如：on a cold morning, on the morning of July 14th?
4、［误］ He became a writter at his twenties
［正］ He became a writter in his twenties
［析］ 这句话应译为：他在20多岁时就成了作家。在某人的一段生活时间段中要用介词in来表示，而在具体岁数时用at来表示。