In this section I will discuss the cognitive functions of the mbti, here is the basic run down
Every mbti type has cognitive functions based on the letters. Think of it as a car, you have the driver or the dominant function which you use the most, then comes the co-pilot. The co-pilot is the second most important function, when making decisions and doing things you should be talking with the co-pilot. Now we have the ten-year-old behind the co-pilot, this is not as dominant as the first two functions but sometimes we will skip over the co-pilot and contact the ten-year-old instead, I'll explain that later. The last function is the three-year-old, you don't typically ask a small child for their opinions in a debate nor should you completely ignore it, that is exactly what this function is.
How to tell which mbti have which functions
The way I do it is first I look at the first letter. If it's introverted the driver is going to be introverted, if it's extroverted the driver will be extroverted. Then I look at the two letters in the middle, which will determine which two are the dominant ones. To find the last two just look at the top two and do the opposite. When figuring out which of the two middle letters comes first just look at the ending letter. If it ends with j and is an extroverted type then the second middle letter comes first, but if it ends with a p and is an extrovert then it starts with the first middle letter. It is reversed for introverts.
I know that was a confusing explanation but it was hard without an example, it will all make sense soon, I promise.