在英语中，it这个词应用的还是比较广泛的，很多地方都会见到it的影子。在学习的过程中，记忆量很大，把握起来相对也比较复杂。所以，今天Stone老师就来聊一聊it在英语中的各种用法。一起来学习吧。
一、it的用法
1.用来指代时间、距离、天气等
It is half past two now.（指时间）
现在是两点半了。
It is six miles from here to the nearest hospital.（指距离）
从这儿到最近的医院有6英里。
It is a lovely day, isn't it?（指天气）
天气很好，不是吗？
2.用来代替指示代词this或that
—What's this? —It's a panda.
这是什么？ 是只熊猫
3.用来指代前方提到的事或没提到但说话双方都明白的事
I had a talk with Mary and it was helpful.
我和Mary谈了一次话，这很有帮助。
4.不知道对方是谁或不知道性别。尤用于打电话、敲门和指代婴儿。
There is a knock on the door, go to see who it is.
有人敲门，你去看看是谁。
Wow! What a lovely baby! Is it a he or she?
哇！好可爱的宝宝啊！是男孩还是女孩？
5.用作形式主语或形式宾语 。真正的主语或宾语用不定式、动名词或从句充当。
It is dangerous for you to swim in the river.
在河里游泳是很危险的。
We feel it our duty to make our country a better place.
我们觉得让我们的国家成为一个更加美好的地方是我们的责任。
6.用于强调句中。It is / was +被强调部分+that / who
It was at the palace ball that Mathilde lost her necklace last night.
昨晚Mathilde是在皇宫舞会上丢的项链。
7.常用it的固定短语或句型
It is a pity / shame that 真可惜
It is no wonder that 难怪
It seems / appears that 似乎
It happens that 碰巧
It occurs to/ comes to / strikes / hits sb. that 某人突然想起
It is said / reported that 所说
It is no use / good doing 做某事没有好处
It is (high) time that......should do / did 是该做某事的时候了
It it the first time that sb. have / has done sth.是某人第一次做某事
It is / has been......since 自从……已经……时间了
It will be / was ......before 还要……时间才
It takes sb. some time to do sth. 做某事花费某人多长时间
see to it that 确保
count / rely / depend on it that 相信
as someone puts it 正如某人所说
when it comes to 提及；谈到
appreciate it if 如果……将不胜
I take it that 我的理解是
二、常见的辨析
it, one , ones, that, those
it经常指代同一个事物，即与前文提到的事物是同一个。如
I can't find my hat. I din't know where I put it. （it就指代前文的hat)
one经常指代同个类事物，即与前文提到的事物是同一类。复数形式是ones。如
Your pen is so beautiful. I also want to buy one.（one就指代前文提到的pen这类事物中的一个即可）
4.that经常用于比较级中，指代一个单数或不可数名词，指代单数时可以与the one替换; 指代复数名词时用those。如
The population of Shanghai is larger than that of Qingdao.（that指代population，不可数名词)
The hat you bought is bigger than that I bought.（that指代hat，可数名词单数，可以与the one替换）
The TV sets we made this year are better than those we made last year.（those指代TV sets，复数）
好了，今天的内容就先聊到这儿吧！有任何疑问或者好的想法，我们评论区再见！