There are times when I received mails from people, here or somewhere, wanting to get to know me or get into my pants. Flattered as I am, I'm often dishearten by their choice of greetings. I don't expect you to speak Queen's English, but at least you have to start off the right foot. I mean, eventhough I know that the email was copied and forwarded to every tom, dick and harry you see, if you can't properly differentiate the hi and hey, the man, guy and dude, it's always best to keep it simple and leave the greetings to just a hi. But then, unless you have a ripped body with a charming face, most people would simply ignore an email with just a hi.
According to the Webster dictionary, hi is used especially as a greeting while hey is used especially to call attention or to express interrogation, surprise, or exultation. Using them by itself constitute a simple greeting, as far as I'm concerned, but when paired with another word such as man, guy and dude, some people screw up big time.
Hi man is wrong, the correct way to go is hey man, preferably with a comma in between but I can live without it. But hey man is mostly used among people who know each other, and you have to throw in a hint of hip hop into the sentence to make it work. So, to hey man a total stranger, I need to imagine you to be heavily hip hop influenced. Same goes to hey dude, where hi dude is somehow incorrect as far as I'm concerned. Both hey guy and hi guy is incorrect usage too, because it should be guys not guy, where you are referring to a group of people instead of one singular person, unless you named yourself after Madonna's ex husband, Guy Richie, then it all make sense.
In support of Greeting Correctly Month.
Dude.... of coz I made that up, DUH~~~~