at the beginning ,in the beginning 什么区别 那个加OF? first first of all firstly 区别是什么啊

1.in the beginning是单独使用作时间状语的.e.g.In the beginning,I couldn't understand what you said.at the beginning of +名词,表示在什么事情的刚开始的时候.e.g.At the beginning of my speech,I'd like to s...