Μην γκρινιάζεις τόσο· αν είσαι λίγο πιο φρόνιμος, θα πάμε στο πάρκο μετά.

Because μην is used for negative commands or negative subjunctive clauses, while δεν is used for simple negation of statements.

So:

• Μην γκρινιάζεις = Don’t whine / Don’t keep whining
• Δεν γκρινιάζεις = You are not whining

In this sentence, the speaker is telling someone not to do something, so μην is the correct choice.

Γκρινιάζεις is the 2nd person singular non-past form of γκρινιάζω, meaning to whine, complain, grumble.

Here it goes with μην, so the whole phrase μην γκρινιάζεις means don’t whine or stop whining so much.

A useful nuance: this form is imperfective, so it often suggests an ongoing or repeated action:

• μην γκρινιάζεις = don’t keep whining / don’t whine like that

A rough pronunciation is:

gree-NYAH-zees

A few helpful details:

• γκ at the beginning is usually pronounced like a hard g in go
• ρι sounds like ree
• νιά sounds like nya
• ζ sounds like z

So the word is approximately gri-NYA-zis.

Here τόσο means so much, that much, or so excessively.

It modifies γκρινιάζεις, so:

• Μην γκρινιάζεις τόσο = Don’t whine so much

Greek often uses τόσο with verbs and adjectives to show degree.

For example:

• μιλάει τόσο = he talks so much
• είναι τόσο καλός = he is so good

Because Greek is a pro-drop language: the verb ending usually tells you who the subject is, so pronouns are often omitted unless they are needed for emphasis or contrast.

In this sentence:

• είσαι already means you are
• πάμε already means we go / we will go

So Greek normally does not need:

• αν εσύ είσαι...
• θα εμείς πάμε...

You could add the pronouns for emphasis, but it would sound more marked.

Literally, it means a little more φρόνιμος.

Breaking it down:

• λίγο = a little
• πιο = more
• φρόνιμος = sensible, well-behaved, good

In this kind of sentence, especially when speaking to a child, φρόνιμος often means well-behaved or good rather than deeply wise or prudent.

So:

• αν είσαι λίγο πιο φρόνιμος = if you’re a little better behaved

That is probably the most natural interpretation here.

Because the adjective agrees with the person being addressed.

Here, φρόνιμος is:

• masculine
• singular

That means the speaker is talking to one male person.

If the speaker were talking to a girl or woman, it would be:

• αν είσαι λίγο πιο φρόνιμη

If talking to more than one person, the form would change again.

This is a very common if-clause + future result pattern.

• αν είσαι λίγο πιο φρόνιμος = if you are a little better behaved
• θα πάμε στο πάρκο μετά = we will go to the park afterwards

So the structure is:

• αν
  • present verb
• θα
  • future main clause

This is a normal way in Greek to express a real or possible condition in the future.

In Modern Greek, θα is the normal future marker.

So:

• πάμε by itself can mean we go, we’re going, or even let’s go depending on context
• θα πάμε clearly means we will go

Here θα removes the ambiguity and makes it future.

Also, πάμε is the 1st person plural form, so it means we will go.

Yes, πάμε very often means let’s go in everyday Greek.

For example:

• Πάμε! = Let’s go!

But in this sentence, it appears as θα πάμε, and once θα is there, the meaning is future:

• θα πάμε = we will go

So here it is not a suggestion or command. It is a future statement.

Μετά here means later, afterwards, or after that.

So:

• θα πάμε στο πάρκο μετά = we’ll go to the park later

Putting μετά at the end is very natural in Greek. Its position is flexible, but sentence-final placement is common and sounds normal.

That mark is the Greek ano teleia, written as ·.

It usually marks a pause similar to an English semicolon or sometimes a colon. So here it separates the two parts of the sentence:

• Μην γκρινιάζεις τόσο
• αν είσαι λίγο πιο φρόνιμος, θα πάμε στο πάρκο μετά

One extra helpful note: in Greek, the symbol ; is usually the question mark, so Greek punctuation can look surprising at first.