They are just greeting rituals. They don't really mean anything in particular. The greeting people choose is a habit pattern, and a little expression of individuality--like the choice of whether to wear a wristwatch or not. They are just friendly noises. "How are you?" literally means "are you feeling well," but you don't actually give a real answer, you just say "Fine, thank you, how are you?" Or people may answer with other vague, individualized answers. I know one person who always says "Pretty good, pretty good," another who always says "Fantastic!" and another who always says "Can't complain." "What's up?" literally means "what things are happening in your life," but it is not a serious question. A friendly, stock, non-answer would be "Not much. What's up with you?" If you want to learn a response, learn that one. Other possibilities are "Life goes on," "Same-old same-old," "Just the usual." The expected answer here is that life has been pleasant but uneventful. You can actually reply with an illogical answer. If someone says "What's up?" and you say "I'm fine, how are you," nobody is even going to notice that it is illogical. They've given you a friendly greeting, you've given them a friendly response. I do NOT recommend that you use this--it is MY little personal answer--but an example of how people personalize their answers in silly, small ways. If someone greets me "What's new with you?" I am apt to say "It's been a quiet week in Lake Wobegon." This is because I know most of the people I know would recognize the reference. It is a reference to a radio comedian, Garrison Keillor, who has a regular monolog on his show called "The News from Lake Wobegon." These are gentle, funny stories about an imaginary, remote, small town in Minnesota. The joke is that the "news" ALWAYS begins with the word "It's been a quiet week in Lake Wobegon." By saying this, I'm saying "it's been

"What's up?" and "How are you?" There are not the same , eventhough for certain sitautions they are supposed to mean the same thing. What's up? = What is happening (to you) ?> How's things ? For general greetings, just say "How are you" For inquiries into what happened/ about a problem/used to ​ask someone what the ​problem is , then use "What's up" What's up with him today ( you are asking why he is acting so different today, for eaxample. When you see someone rushes to you as if your help is reqiured , you can say "Whats up?" before the person starts speaking

"What's up" is more informal than "How are you" :) E.g friends would rather say "what's up" instead of "How are you" but it basically means the same :) Just answer with how things are going :) like are you good, sad, angry so on, and maybe answer with what you are doing :) Hope it helped.

I won't answer your "what's up" question because other people have already. However here's some more useful greetings that are seldom taught at school or in textbooks, but are very common! These mean "How are you?", but are less formal: How's it going? *How's things? **Alright? How have you been? When answering those, keep in mind that "I'm fine, thank you, and you?", is VERY formal-sounding. You may say instead: Fine thanks! Good thanks! Not bad! ...all may be followed with "You?" (rising intonation, because it's a question) Another common one is "What have you been up to?". For that, you can tell the asker something you did recently, just a sentence or two is fine. ------ *You may notice the grammar there is non-standard. You may say "How are things?", but "How's things?" is more common. **This is VERY British! An American might have no idea what you're talking about.