While lexicographers may point to the relative poverty of the Slovak vocabulary when compared to the English (approx. 220,000 words to 450,000), there are certain areas in which the Slovak language excels. One of these is ways of saying hello and goodbye. I offer here a personal guide to some of my favourites.
"Dobrý deň" (good day) hardly needs any introduction. Ideal for use with elderly neighbours and pleasant shop-assistants, it can be suffixed by the word prajem (I wish) for extra effect. While some people may be inclined just to say "dobrý" (leaving out the deň), I think it sounds insincere and advise avoidance of this lazy habit.
Occasionally you may hear the word "bozkávam" (I kiss), or even "ruky bozkávam" (I kiss your hands) a very formal greeting with almost Shakespearean overtones. Also in some villages, you may hear people greeting each other with the words "pochválen buď Ježiš Kristus" (Jesus Christ be praised). This is very striking the first time you hear it, and carries the same old-world gravitas as when children use the formal you - vy - form with their parents.
"Dovidenia" is the polite goodbye, though "zbohom" (with God) can be used if you are walking out on your job/loved one and wish to create a nice 'adieu' effect. "Dovi" is OK and more acceptable a diminutive than "dobrý" (see above) in that it can be very nicely enunciated. For advanced Slovak learners, "dopočutia" (literally 'till I next hear you' and used to say goodbye on the phone) will impress the natives, as should "dopo", though be careful to pronounce this properly as it can sound silly if you get it wrong.