1. First, parents teach a person his mother tongue. Starting with the words "dad, mom, grandmother, grandfather" and the sounds of animals. Then he (she) goes to school where he begins to teach him more deeply, learns the rules, new words, etc.

2.As a rule, it is English or German. Less often - French, Spanish. I cannot answer the specific answer to the question of why these languages were the most popular, but perhaps because they were studied in schools earlier, perhaps because of this they were the most popular.

3. Firstly, if a person wants to enter some good foreign university, then you definitely need to know at least English. Secondly, to move to live in another country. To do this, you need to know the language of the country, of course, you can not learn the language the country speaks and live in the "Russian region", but I think it's not so interesting.

4.

It can be used in the city, shop, communicating with a person. Let's take an example: you don't know English and Will Smith himself comes up to you and says -Hi, how are you? And you’re not such a guy / girl, my producer wants to enroll me for the shooting of the film, but what kind of guy / girl is needed there and you will fit very well there, how do you like my idea? And you as evil do not know English and stand in a stupor. Therefore, to prevent such a situation from happening, you must at least learn English.

5. Probably because it's native. This is a piece of the soul. What you have been taught for years. Therefore, it is important not to forget your national language!