I think that the problem is when the μ is printed as u?

Question

Sometimes a see a letter that looks like u when an accent mark on it.
I have seen this kαληνuχτα or could it be spelled as καληνχτε?
In the first version of the word, there is an accent mark above the "u". Could that be a typo?

Answer 1

μ and υ are two completely different letters. μ is Mi; υ is Upsilon, which is a vowel

The first spelling of καληνυχτα, with the accent mark over the υ, is correct. It means "good night." The second spelling is not a word; it is not pronouceable in Greek at all, unless it's slang.