Grammar point: time words
以前 (yǐqián), 以后 (yǐhòu), 终于 (zhōngyú) and the rest of the words that place an event in time, along with where in the sentence they go.
以前 (yǐqián), 以后 (yǐhòu), 终于 (zhōngyú) and the rest of the words that place an event in time, along with where in the sentence they go.