What does the word "them" in line 3 refer to?

As to my sad personal life, one of the most … - asked questions is why I can’t stay even in a simple, friendly relationship for a long time

When scientists talk about children language learning at the early ages of their lives, they mean the way in which the child needs no special skill to learn his mother tongue. Every thing happens just through observing and experience. That is why a kid gets an absolute fluent native speaker without any negative point. Researches show that only 5 percent of little children in a society have learning problems.

Now let us to jump into second language learning. Here we can talk about skills. Some people are good at written skills while others are good speakers. Besides these two main abilities, we can also mention listening and reading which can be improved by reading storybooks or watching movies; however, the learning speed may vary from person to person.

When a foreign language is beloved, people work hard to learn it better and faster because they do not hate it and they like it.

Which one is NOT true about language learning?