A phrasal verb consists of a verb with an adverb or preposition or both, which alter the original meaning of the verb. A phrasal verb is usually an idiomatic or less formal way of saying something and, as such, can be a bit confusing for those learning the language.

For instance, we might say, "he looked up at the sky" and looked up is not a phrasal verb but literally means that he looked upwards. However, we might also say that "he looked up the word in a dictionary" and in this case, he wasn't looking upwards at anything - he was searching for information. This is a phrasal verb.

Sometimes, just to be extra-confusing, the object can come between the verb and the particle (the bit that comes after the verb). For instance, “he looked the word up in a dictionary”. There aren't any hard and fast rules for this type of verb separation; basically use what sounds or feels right. It's just something that you will pick up as you go along. (Did you see the two phrasal verbs in that sentence?)

English has a lot of phrasal verbs that don't translate literally. Here are just a few:
• to get over = to recover from
• to run into = to meet (unplanned)
• to back down = to admit to being wrong or defeated
• to study under = to be taught by

Here is a complete list of phrasal verbs

Why should you learn them? Because they form an integral part of the English language as spoken every day. They also appear in most writing, except the very formal. Unless you are comfortable with them, you may find yourself scratching your head and asking questions like, "What does up (or into, or down, or under) mean in this sentence?". Apart from understanding phrasal verb usage, another reason you should learn some is so that you sound more fluent and comfortable with the language.

You shouldn't worry about memorising loads and loads of them right now, there are too many. However, get familiar with the idea of these phrases and consider the rest of the sentence, as well as the sentences before and after, for a general idea of what they mean. If you are speaking English frequently or reading English stories and books, idioms will get easier and easier for you.
While you mightn't have to learn hundreds of them, it would be wise to be familiar with at least a few commonly used phrasal verbs to use when speaking or even writing.

Here's why they're difficult:

• They barely exist, or don't exist at all in a lot of languages.
• Each phrasal verb can have several different meanings.
• They can be separable or non-separarable, or both.

Here's an example:

Break up - It can mean to separate something into pieces, or to end a relationship, depending on how it's used (how is that for different meanings!?!)

So:

I hope my girlfriend doesn't break up with me.
In the sentence above, the verb is used to mean "end a relationship." It is non-separable in this case, meaning that you can't write break with me up.

I need to break these stones up.

Here it is used to mean "separate something into pieces" it is also both separable and non-separable with this meaning, so you could write "I need to break up these stones."

More on Phrasal Verbs

Phrasal Verbs-http://engtuto.com/phrasal%20verbs/

Author's Bio: 

Sunil Rajpal

Phrasal Verbs-http://engtuto.com/phrasal%20verbs/