Foreigners often make some strange mistakes in Chinese when they study the most difficult language— —Chinese. We try to analyze typical sentences to correct these errors.
       Cóng shàng dàxué de shíhòu yǐ lái, wǒ yì tiān jiǎ yě méiyǒu qǐng guò.
False: 从上大学的时候以来，我一天假也没有请过。
         Cóng shàng dàxué yǐ lái, wǒ yì tiān jiǎ yě méiyǒu qǐng guò./Shàng dàxué de shíhòu , wǒ yì tiān jiǎ yě méiyǒu qǐng guò.
True: 从上大学以来，我一天假也没有请过。/上大学的时候，我一天假也没有请过。