The examples you give are "real language" for some people but not for
everybody or every situation. Some forms of the spoken language are
not well accepted in business use or in schools or in other situations
where the rules are important. The examples of "real language" that
you cite are among those.
You have found these examples in popular songs and on TV. Certain rules
of grammar that you have been taught are not followed; in fact, different
For example, the accepted forms of "he doesn't," "she doesn't," and
"it doesn't" are not used in the "real language" you cite; instead,
the forms "he don't," "she don't," and "it don't" are used ("He don't
love me") as well as the double negative ("I don't got no money").
While both "don't" in the third person singular and the double negative
were widely used in earlier times, today these rules are considered
to be "nonstandard." Some people feel that they show the speaker
to be uneducated in the use of "good English." So why do you hear such
language in songs and on TV? The singers and actors and much of their
audience use this kind of language naturally, and indeed, it is one
form of English. It may be that they are comfortable with this kind
of language, or prefer to keep using it, thereby sending the message
that they are just ordinary people, part of the working class, not highly
educated and not trying to be better than anyone else.
The dialect or form of language that a person uses comes from various
sociological and psychological forces in his/her background. Political
issues are also an influence. Among some people, it's correct to speak
the "real language" you refer to, and speaking another way could be
considered false or snobbish. However, if you are going to school in
an English-speaking country, or working or doing business with English
speakers, people will note that your English is nonstandard. The fact
that you speak in a nonstandard way could, realistically, impede your
chances of advancement in work. Socially, too, many people who value
"correct" English might count this against you.
Which way should you speak? You should be comfortable with the people
you are interacting with, and use the language that they do. As a non-native
speaker, you are wise to be sensitive to the differences in dialect.