The advantages of learning languages are widely known and acknowledged, so I needn't mention them here.  One of the disadvantages of learning a foreign language is the incredible consumption of time that must be expended learning it, just to be able to speak it passably well.

advantages: you can develop a self-determination; capability to converse with different people in a specific language; you gain friends and power to easily understands the langauge more than any common people have..

disadvantages: there is a 95% that you easily forgot your native language if you will immerse yourself into the focus of learning a foreign language.

My native language is TAGALOG, I know how to converse in ENGLISH; I'm currently learning Korean and spanish.
The trouble is, I nearly forgot how to respond in english and I suddenly think in Korean (thats' teh disadvantage for me.)

I think you only get advantages, you will learn more about songs, movies, and cultural information, It reminds me at the time when I was a child and I was learning Spanish, I was eager to chat with somebody Constantly I asked many questions, A few time before I used to hate learning languages because I found it very difficult and I hated that English has many grammar rules, but now I am more worry about my fluency, my communication than by my mistakes. 

In fact, there are no disadvantages of learning foreign languages, on the contrary, it makes us improve our skills and let us meet new friends

Learning foreign languageas have a lot of advantages such as connecting , meeting and sharing many people. I think learning foreing languages have no disadvantages ...