This is the third article from the series "MQL4 Language for Newbies". Now we will learn to use built-in functions and functions for working with technical indicators. The latter ones will be essential in the future development of your own Expert Advisors and indicators. Besides we will see on a simple example, how we can trace trading signals for entering the market, for you to understand, how to use indicators correctly. And at the end of the article you will learn something new and interesting about the language itself.