请问look，look at,have a look的区别？

Look 是一个动词，相当于汉语中的 看啊！！Look,here comes the bus.Look,there is a house.
Look at 是一个词组，look这里是动词。加了一个介词，就是看得有东西 Look at the blackboard,please. Look at the sky. (当look at 后面是一个副词 如 here there 时，at 不能加)
Have a look 是一个词组 look这里是一个名词，顾名思义，来个看，就是看一眼，看一看的意思。 Could I have a look? Let`s have a look.

look只是指单纯的“看”，动词，是“不急物动词”。后面必须搭配“at、for、like、out”等介词
1.look at “看着某物”e.g. Look at the blackbord please.请看着黑板
2.look for“寻找”e.g.She is looking for her cat.她正在找她的猫。
3.look like “……看起来像……”e.g.She looks like her mother.她看起来像她妈妈（指长相上）
4.look out“往外看”e.g.Don't look out of the window when you are in class.在你上课的时候不要往窗外看。

have a look 指“看看”的意思。比如：Let me have a look at your hands.让我看看你的手，have a look可以等同于look at的意思，都是表示看看的意思