初二英语介词of for at with这几个介词该怎么用?请详细跟我说啊,

of.的,比如a photo of my family.它可用作名词所有格,表示无生命的for为了.,for my sonat表示在什么边,固定搭配at homewith和.,i will go to school with my friendof 是用在不可数名词,e.g.a cup of coffeefor 是为...