请问before和in front of,in the front of有什么区别

You can't buy them in the shop before eight o'clock。八点之前你在商店里买不到那些东西。How many students stand in front of the class? 有多少学生站在同学们面前。[辨析] before与 in front of都有“在。之前”的意思,当表示“在某种位置前”时,两者可以通用。例如：She sits before/in front of me in the classroom。在教室里他坐在我的前面。in the front of是只在前面的部分They are standing in front of/before the blackboard。他们正站在黑板的前面。当表示“在某建筑物前面”时,宜用in front of。例如：The car stopped in front the cinema。 汽车停在电影院的前面。当表示“在某段时间”,“某一事件”之前时,用before,不用in front of。例如：Before liberation he lived a poor life。解放前他过着贫穷的生活。Please come to see me before Sunday。请在星期六以前来看我。