基础英语，英语基础。
只有扎扎实实学好词汇用法，才能真正掌握一门外语。
in
1. 做介词，用来表示某人或某物“在哪里”
Carlos was in the bath.
卡洛斯在洗澡。
I wanted to play in the park.
我想在公园里玩。
In New York we saw the Statue of Liberty.
在纽约我们看到了自由女神像。
His company is one of the biggest in the world.
他的公司是世界上最大的公司之一。
2. 做副词，表示某人进入...；或某物被放到什么里面
Someone knocked at the door, and Hana called 'Come in!'.
有人敲门，哈娜说：“进来！”.
She opened her bag and put her phone in.
她打开她的包然后把她的电话放进去。
3. in用来表达时间：
In常常表达一段时间：
He learned to drive in six months.
他在六个月内学会了开车。
The food was all eaten in a few minutes.
食物几分钟就吃完了。
将来时里 in 表达多长时间后：
In another hour it will be dark.
再过一个小时，天黑了。
in 还用来表达什么期间发生：
In 1872, there was a terrible fire in Chicago.
1872年，芝加哥发生了一场可怕的火灾。
Her birthday is in April.
她的生日是四月。
We plan to go camping in the summer.
我们计划在夏天去野营。
in 表达泛指的上午，下午，晚上：
I often go swimming in the morning.
我经常早上去游泳。
Dad used to sit there in the evening and listen to the radio.
爸爸过去常常晚上坐在那里听收音机。
但是不要说in the night要用at night：
There were no lights in the street at night.
夜里街上没有灯。
注意!
发生在具体某天，及其上下午晚上，要用on 表达时间：
On Tuesday they went shopping.
星期二他们去购物了。
Ali was born on April 10th.
阿里出生于4月10日。
注意!
美国人有时候省略on:
I'm going to a party Wednesday.
我星期三要去参加一个聚会。
注意!
表示某事持续了一段时间，不用in,要用for:
I have known you for a long time.
我认识你很久了。
I worked for the same company for ten years.
我在同一家公司工作了十年。
4. in表示"穿着/戴着”
The bar was full of men in baseball caps.
酒吧里都是戴着棒球帽的男人。
来源: Collins COBUILD English Usage © HarperCollins Publishers 1992, 2004, 2011, 2012