把 has two main usages. The first of which is a measure word for things with handles like knives 一把刀, and the other one that springs to mind is 一把椅子 a chair. The best translation of 把 in English is "to take (this object) and do something to it". 把 is often used when talking about moving objects,. For example: 我把電腦放在桌子上 I put the laptop on the table 他把書放在書架上 He puts the book on the bookshelf 我把鉛筆弄丟了 I lost my pen 我把可樂放在冰箱裡 I put the coke in the fridge 把 is also commonly used in instructions or commands. 把作業交上來！Hand your homework in! 把殺手送上死刑台 lit. to take the killer and send him to death row 把小偷給抓住！Capture the thief 你把房間歸置歸置一下唄 - clean your room up a bit It can be used to clear up ambiguity 我喝完了酒 means both "I am finished drinking the alcohol (or wine)" and "I finished drinking the wine" (there is no wine left) When you say 我把酒喝完了 this means there is no wine left. Similarly 我把牛排吃完了 I ate all the stake 我把殘羹剩飯一掃而光了 - I ate up all the leftovers It can also be used when talking about the physical effects on people or objects 他把他的女朋友給打死了 He killed his girlfriend 他把我的橡皮弄斷了 He broke my rubber 千萬不要把這件事說出去 - don't tell anyone (about) this 我沒有把消息告訴他 - I have told him (that thing) (yet) http://www.zybang.com/question/5a721c2fd971fab040419e54459047e7.html this article on Baidu is pretty good, and aimed at foreigners.

It's important to note that 把 has other uses. The most common is as a measure word for things with handles, or things that you hold. Examples include 一把伞, 一把枪 and 一把椅子. So, you've got to look at how 把 is being used in a sentence before you can understand its meaning. To demonstrate the difference, here's a sentence with both kinds of 把 in: 请 把 那 把 伞 拿 给 我。 Qǐng bǎ nà bǎ sǎn ná gěi wǒ. Please give me that umbrella. Hope it is helpful !

hello，I wiil give you some example. “把”可以是动词，量词，名词 如： 父亲对儿子说：“把（1）住门或拿把（2）锁锁住门,别让贼把（3）车把（4）偷走了 1、动词（此处把住门同守住门的意思） 2、量词（锁的数量可以用把表示） 3、动词 4、名词（车把是车的一个部位） 其他例子： 动词 1.请你把门关上； 2.请你把杯子递给我； 量词 1.你有几把钥匙； 2.一把白菜（意思：一捆白菜） if you have any question，please contact me