HI everybody Whassup? Wow, I think many people would be familiar with the greeting “whassup” if they are interesting in American Soaps. This kinds of word can’t be checked in a dictionary, or using on formal essays. But it is increasingly popular among English speakers, because this kind of greeting sounds more nature and more like words between closing friends. So today I’d like introduce some American greeting words. Hope that may helps you and give you some fun.
“HOWDY”  
Commonly relegated to the down-home boys of the Southern states and Western movie stars like John Wayne, “howdy” is an informal greeting often thought to represent a shortened version of the phrase “how do you do?” Generally thought of as a hallmark of the vocabulary of states such as Arizona, Texas and New Mexico, it is believed to have come from Native American greetings to settlers. 
“WHASSUP”
  “Whassup?” “What’s up?” “Sup?” They all mean the same thing. This is an informal slang greeting you’ll hear in many places across the United States, basically meaning: “How’s is everything going?” The long slurred form of the phrase “whassup” gained popularity in the 1990s from a series of well-loved beer advertisements, where characters tried to outdo each other with progressively longer “whassaaaaps”. 
“YO”
  Short, sweet and to the point, the one-syllable “yo” might be the simplest American greeting in the English language. The word originally came from Philadelphia, Pennsylvania – a largely working-class city in the Northeast – but a series of iconic uses popularized the word in the American vocabulary. Most famously, Rocky Balboa, the main character in the titular “Rocky” films, used the word as a sign of his Philadelphia roots. The word also gained wide usage in the hip-hop and rap communities in the 1990s, filtering into the mainstream conversation through the popularity of that lifestyle and music. 
“ALOHA”
You might need to head to a tropical paradise to hear this island greeting. “Aloha” has been used in the island state of Hawaii since the mid-19th century to mean not only a greeting, but also a farewell. In the decades since then, Hawaii has become quite the tourist destination – with countless visitors to the “Aloha State” getting a taste of the island lifestyle and bringing back a phrase or two home with them.
“SHALOM”
“Shalom” is a greeting normally used in the American Jewish community. It comes from the Hebrew word for peace, completeness, prosperity, and welfare – and just like “Aloha”, it can mean both hello and goodbye. It is frequently used as a more general blessing, and is often put in combination with other Hebrew words in both colloquial and religious contexts.