Greetings - Formal and Informal

There are always two levels of people based on age..

• The people who are younger than us.
• The people who are elder than us..

There is a difference while we greet or wish them..

For people, who are younger than us, we wish as...

HI!           HELLO!            HOW ARE YOU?!             WHAT'S UP?!          HOW ARE YOU DOING?

For people who are elder than us, we wish as,

GOOD MORNING/AFTERNOON/EVENING             NICE TO MEET YOU....                GLAD TO MEET YOU.....  

Note : a gesture of hand shake / folding/locking hands is common while wishing elders.

High-five, waving hands, etc are  common while talking to young ones.

Ending conversation: 

For the younger people, we say,

SEE YA!                   HAVE A NICE DAY......                KEEP IT UP..               ENJOY THE DAY.....

ALWAYS BE CAREFUL..

For elders, we say,

THANK YOU!           I WILL FOLLOW YOUR WORDS.