You can use "em" to call somebody if you know (or guess) he/she is younger than you as well as vice versa, call yourself if you younger than him/her In some cases for respecting the others (example: your child's teacher, your boss, higher authorities...) DO NOT use this word even if they are indeed younger than you, just call "anh","chị"... At last, I want to notice you: the address form is very very complex in Vietnamese, sometime we even call the opposite side completely based on feeling

HELLO, How are you today.my name is penda ,i saw your profile today and became intrested in you,i will also like to know you more,and i want you to send an email to my email address so i can give you my picture for you to know whom i am. Here is my email address ([email protected]) I believe we can move from here! I am waiting for your mail to my email address above.. (Remeber the distance or colour does not matter but love matters alot in life) yours in love, Penda.

Well, saying you can use "em" for people who are younger than you is inexact. In fact, you use "em" for people who are: - Your younger brothers/sisters and your parents' younger brothers/sisters' children... (even if they are older than you). - Younger than you about 10 years old or less, just younger is NOT enough, an oldman can not call a baby "em". - Your girlfriend(s)/wife(s)/lover(s)/sexual partner(s) (even if they are older than you). In some cases, you can use "em" to devalue a person, be careful though, also can you with closely related friends for joking only. And of course, you call yourself "em" vice versa.

"Em" is used with your lover or your friends who u know for sure they are younger than you. If you meet someone in social network or in working, even they are younger than you, its better that u call them "Chị" or "Anh" . Its the safe and formal way