Bad Words in English

There is an assistant language teacher from America in our school.
She comes to our school only on Tuesdays.
For the rest of the weekdays, she works for different schools in the area where our school is.
Yesterday, after work, I learned English bad words from her.
She kindly wrote them down on a sheet and explained them dividing in five levels.
The words of level one can be used by children but level five words can cause fighting.
I’ve heard most of the expressions, but some of them were not familiar to me.
There aren’t any foreigners expect her so nobody understands the English bad words in the school.
I will try to use the minor ones at school to get used to the bad words.