what it is 和 what is it的区别：含义不同、用法不同。what it is中文翻译为“某事的原因”，是名词性从句，不能以问句形式出现，一般作为句子的一部分；what is it中文含义为“这个是什么”，是一个单句，可以单独使用。
一、what it is的含义及用法
what it is含义为事实真相，原因，理由。例句有：
1、I have known what it is like to go without food for days
我知道几天没有东西吃是什么滋味了。
2、Please gratify my curiosity and tell me what it is.
请满足我的好奇心，告诉我那是什么。
3、The youngster just doesn't know what it is to be tired.
这小伙子有一股子使不完的劲儿。
4、I don't think it makes a lot of difference what colour it is.
我认为颜色无关紧要。
5、You don't have to get up early in the morning; what bliss it is!
你早上不用早起，多么幸福啊！
6、What it will do is create a whole new ruling class.
它的作用就是创造一个全新的统治阶级。
二、what is it的含义及用法
what is it含义为它是什么，这个是什么。例句有：
1、What is it you want to see me about?
你找我有什么事？
2、What is it like to steer a ship this size?
驾驶这么大的船感觉怎么样？
3、What is it like riding a bike using sonar?
用声纳骑自行车是什么感觉?
4、What language is it they're speaking?
他们讲的是什么语？
5、Of what use is it to separate art from politics?
艺术脱离了政治，那么这个艺术还有什么用处？
6、What beats me is how it was done so quickly.
使我困惑不解的是，这事怎么这么快就完成了。
