"But which one is the best?" Fahad demands, between plaintive and playful. "When I go into the coffee shop, which one should I say to the man?"
"It really depends."
"But here, in Canada."
"I know! It depends. On me--how I feel; on the other person--Do they speak English as a first language? Are they stressed? Relaxed? Is there a connection?"
Fahad isn't impressed.
"Ok. If you say 'Hey,' then you let the person know that you speak English pretty well. Because Level 1 kids only say 'Hello'--they see it in the textbook and their teacher greets them with it, even though no one says 'Hello.'"
Now I have his attention.
"From a native speaker, 'Hello, how are you?' is basically another way to say, 'You obviously don't speak English as a first language.' 'Hi' is better. 'Hey' is probably best, unless you don't like the person."
More attention still.
"Because it's so short. The longer the greeting, the more you like the person. 'Heyyyyyyyyyy' means 'I'm your friend. I'm really, truly happy to see you.' If you hate the person, 'Hi' [clipped, short, a blow dart]."
Fahad and I practice our super-long 'Heyyyyyyyyyyyys.'
Because friends don't let friends say 'Hi.'