Answer: The answer is informal slang.
All of the following are learned in world languages informal slang.
Explanation: Slang refers to an informal language used between people who are familiar with one another and belong to the same social group. It can offend people if it is used outside the social group of people who know one another. Slang is used rather than writing. Slang changes quickly with time and its words and expressions can disappear from the language.
