Here is how the three negating words are used in the language.
δε / δεν : Verb negation
The way you negate a verb is by placing δεν in front of it. In case the verb takes a direct or indirect object – or both – in the form of a pronoun, the pronouns go between δεν and the verb.
Δε μιλάει πολύ. – She doesn’t talk much.
Δεν τον βλέπω. – I don’t see him / I can’t see him.
Δεν της λέει τίποτα. – He’s not telling her anything.
Δεν του το ζήτησα. – I didn’t ask him for it.
If the objects – direct or indirect – are not pronouns, then they don’t intervene between δεν and the verb.
Δε διάβασα το βιβλίο. – I didn’t read the book.
Δεν το είπα στη Νίκη. – I didn’t say it to Nikki. / I didn’t tell Nikki about it.
μη / μην : A. Verb negation after να B. Negation of the imperative
C. Prefix ‘non-‘ D. Negation of active participles
The negator δεν will become μην after the word να. Compare:
Δε θέλω να βρέξει. – I don’t want it to rain.
Θέλω να μη βρέξει. – I want it to not rain.
The English structures to not and not tο are generally translated as να μην in Greek, which makes sense since να in most cases performs the same function as English to.
Μας είπε να μην έρθουμε. – She told us not to come.
Αποφάσισα να μην περιμένω. – I decided to not wait.
Note that δεν and μην share the same syntax rules when it comes to verb objects, both for this usage (A), as well as for the one that follows (B).
Αποφάσισα να μην τον περιμένω. – I decided to not wait for him.
Αποφάσισα να μην περιμένω το λεωφορείο. – I decided to not wait for the bus.
The most common use of μη / μην is introducing a prohibition.
Μη φεύγεις. – Don’t leave.
Μην το αφήνεις. – Don’t let go of it.
Μη μου το δίνεις. – Don’t give it to me.
Note, however, that when μην is employed, the verb is not in the imperative, but in the indicative.
Φύγε! – Leave!
Άσ’ το! – Let go of it!
Δώσ’ μου το! – Give it to me!
English compound words like non-existent or non-smoker, in Greek are formed by using μη, which is always used without a hyphen and without the final -ν.
μη υπαρκτός – non-existent
μη καπνιστής – non-smoker
Consider the following examples:
Έφυγε, μην ξέροντας πού να πάει. – He left, not knowing where to go.
Μην έχοντας δει τι έγινε, βγήκε έξω. – Not having seen what happened, she went out.
In the two sentences, μην ξέροντας and μην έχοντας δει can be rewritten as: χωρίς να ξέρει ‘without knowing’ and χωρίς να έχει δει ‘without having seen’. This explains why μην is employed here, since it is essentially a negation after να, like in (A).
όχι : i. The word for ‘no’ ii. Negation for everything else expect verbs
When a yes-or-no question is asked, όχι is the negative answer.
Το όχι σημαίνει όχι. – No means no.
While δε / δεν negates verbs, όχι negates everything else: adjectives, adverbs, nouns, pronouns, participles, even entire sentences.
Όχι αυτό, το άλλο. – Not this one, the other one.
Όχι μεγάλη, αλλά οργανωμένη. – Not large, but organised.
Όχι τόσο καλά. – Not so well.
Όχι, δε θέλω. – No, I don’t want to.
Όχι, δε σου είπα να μην μπεις. – No, I didn’t tell you to not go in.