Its
Its is short for it is or it has Its是it is或it has的缩写形式
1. Its been raining for a week.
（It has been raining for a week.）
已经下了一个星期的雨。
2. Its a nice song and I think it will catch on quickly.
（It is a nice song and I think it will catch on quickly.）
这首歌很好，我想它会很快流行起来。
3. Its worthwhile to learn English.
（It is worthwhile to learn English.）
学英语是值得的。
4. Its been ten years since she left her hometown.
（It has been ten years since she left her hometown.）
她离开家乡已经十年了。
Its
Its is like his and her Its的用法跟his和her的用法一样
1. You cant judge a book by its cover.
不能以貌取人。
2. Each region has its own customs.
每一个地区都有它自己的习俗。
3. The west lake is noted for its scenery.
西湖以其风景优美而著名。
4. The company is running down its sales force.
这家公司正在裁减销售人员。
【注意】
1. Its只可能是it is或者it has的缩写，并不等于it was。
2. Its是形容词性物主代词，具有形容词的特性，常放在名词前作定语。