* Slang is highly context-dependent: It's tied to specific groups, regions, and even time periods. What's slang in one place or among one group might not be understood by others.
* Slang can evolve rapidly: Words and phrases enter and leave the slang lexicon quickly.
* Slang is often creative and playful: It uses wordplay, metaphors, and other linguistic techniques to express ideas in a novel way.
* Slang doesn't follow standard grammar rules: Slang expressions often break the rules of standard English, using contractions, unusual word order, or invented words.
In short, while slang can be informal, it's more than just a casual version of standard English. It's a dynamic and evolving system of language that has its own rules and quirks.
Think of it this way: Standard English is like a formal dictionary, while slang is like a constantly updated street dictionary. Both are useful in their own way, but they serve different purposes.