Elaine is generally right, however I'd like to make some remarks grammar-wise.
1. "Δε(ν)" is used in the indicative mood.e.g.
Δεν πήγα στο σχολείο σήμερα. = I didn't go to school today.
2. "Μη(ν)" is used in the subjunctive mood.e.g.
Θα προτιμούσα να μην πάω στη δουλειά σήμερα. = I'd rather not go to work today.
3. The imperative mood does NOT have a negative form, so we use μη(ν) + subjunctive in order to form negative commands.e.g.
Μην τρέχεις! = Don't run!
Μη φύγεις! = Don't leave!
4. Like Elaine has already said, to render the word "not" as in "I love her, not him" into Greek, the word "όχι" (= no) is used.e.g.
Θα ταξιδέψω στην Ευρώπη, όχι στην Ασία. = I'm traveling to Europe, not Asia.
Θέλω να κοιμηθώ, όχι να χορέψω. = I want to sleep, not dance.5. To form negation with participles, adjectives and nouns, the word "μη(ν)"* is used.e.g.
Μη γνωρίζοντας τι να κάνει, άρχισε να προσεύχεται. = Not knowing what to do, he started praying.
Το μη εξουσιοδοτημένο προσωπικό δεν πρέπει να εισέρχεται σε αυτόν το χώρο. = Unauthorized (non-authorized) personnel must not enter this room.
Ο χρήστης είναι μη ενεργός. = The user is non-active.
Οι πνεύμονες ενός μη καπνιστή είναι καθαροί. = The lungs of a non-smoker are clean.
NOTE:
The words "
μη(ν)" and "
δε(ν)" sometimes drop the final
-ν, while other times they don't.
The rule says that these words retain the final
-ν when the next word begins with a vowel or one of these consonants:
κ,
π,
τ,
ξ,
ψ,
μπ,
γκ,
ντ,
τσ,
τζ.
e.g.
Δεν ξέρω. = I don't know.
Δε θέλω. = I don't want.
Μην ντρέπεσαι. = Don't be shy.
Μη μιλάς. = Don't speak.*An exception to this rule is that when forming negation with past participles, adjectives and nouns, we use "
μη" without the final
-ν, even if the following word begins with a vowel or one of the aforementioned consonants.
e.g.
μη ελεγμένος = not checked / not tested
μη πιστευτός = non-plausible
μη καπνιστής = non-smokerI hope I helped you.