Μην στενοχωριέσαι τόσο· θα σε πάρω μόλις τελειώσω.

Because μην is used to negate a command, request, warning, or wish.

So:

• Μην στενοχωριέσαι = Don’t be upset / Don’t worry
• Δεν στενοχωριέσαι would mean You are not upset / You aren’t worrying

In other words:

• δεν negates statements
• μην negates commands and subjunctive-type clauses

Here the speaker is telling someone not to worry, so μην is the right choice.

στενοχωριέσαι is the 2nd person singular form of στενοχωριέμαι.

It means something like:

• you are upset
• you get upset
• you worry / feel distressed

A useful thing to notice is that the dictionary form is often στενοχωριέμαι, not an active form. This is very common in Greek with verbs about feelings or states.

Related forms:

• στενοχωριέμαι = I am upset / I get upset
• στενοχωριέσαι = you are upset / you get upset
• στενοχωριέται = he/she is upset

There is also an active verb στενοχωρώ, which means I upset someone:

• Με στενοχωρεί = It upsets me

So:

• στενοχωρώ κάποιον = upset someone
• στενοχωριέμαι = be upset

In Modern Greek, negative commands are normally not made with a special imperative form. Instead, Greek uses:

μη(ν) + subjunctive-type form

That is why you get:

• Μην στενοχωριέσαι
• Μην πας
• Μην το κάνεις

So even though the meaning is a command or request, the grammar is not the same as a positive imperative.

Compare:

• positive: Ηρέμησε = calm down
• negative: Μην ανησυχείς = don’t worry

This is completely normal Greek structure.

τόσο here means so much / that much / so.

So Μην στενοχωριέσαι τόσο means:

• Don’t worry so much
• Don’t be so upset

It focuses on the degree.

Compare:

• πολύ = much / a lot / very
• τόσο = so much / that much / so

In many situations both can appear, but they are not always identical in tone.

For example:

• Μην ανησυχείς πολύ = don’t worry a lot
• Μην ανησυχείς τόσο = don’t worry so much

τόσο often sounds a bit more natural when reacting to someone who is clearly very worried.

Yes, the basic meaning of παίρνω is take / get / pick up. But in everyday Greek it has several common meanings, including:

• take
• pick up
• bring
• call someone (on the phone)

So θα σε πάρω can mean different things depending on context, such as:

• I’ll call you
• I’ll pick you up
• I’ll take you

In this sentence, the meaning you were given is the one to follow, but the important grammar point is that παίρνω is a very flexible everyday verb.

This is one of those verbs where context matters a lot.

Because σε is a weak object pronoun meaning you, and in Greek these pronouns usually come before the finite verb.

So you get:

• σε βλέπω = I see you
• θα σε πάρω = I’ll call/take/pick you up
• να σε δω = for me to see you / let me see you

Not:

• θα πάρω σε ❌

A very important exception: with an affirmative imperative, the weak pronoun usually goes after the verb:

• Πάρε με = take me / call me
• Πες μου = tell me

But here the verb is part of a future construction with θα, so the pronoun stays before the verb:

• θα σε πάρω

This is about aspect, which is very important in Greek.

Both πάρω and τελειώσω are perfective non-past forms. They usually refer to a single complete event.

Here that makes perfect sense:

• θα σε πάρω = I will call you / pick you up once
• μόλις τελειώσω = as soon as I finish completely

If you used the imperfective forms, the meaning would change:

• θα σε παίρνω = I will be calling you / I will call you regularly
• τελειώνω can sound more like a repeated or ongoing situation in the right context

So the speaker chooses:

• πάρω for one complete future action
• τελειώσω for one completed action before the next one happens

This is one of the biggest differences between Greek and English: Greek often forces you to choose between completed and ongoing/repeated action.

Because after μόλις meaning as soon as, Greek normally does not use να.

So the natural pattern is:

• μόλις τελειώσω
• μόλις γυρίσει
• μόλις φτάσουμε

These mean:

• as soon as I finish
• as soon as he/she comes back
• as soon as we arrive

So even though τελειώσω looks like the same kind of form you may have seen after να or θα, here μόλις itself is enough.

You can think of μόλις as a word that triggers this kind of verb form without needing να.

τελειώσω is the 1st person singular perfective non-past form of τελειώνω.

In practical learner terms, it is the form used in patterns like:

• θα τελειώσω = I will finish
• να τελειώσω = for me to finish / that I finish
• μόλις τελειώσω = as soon as I finish

So although English learners often first meet it in the future, it is not just a future form by itself. Its meaning depends on what comes before it:

• θα
  • τελειώσω → future
• να
  • τελειώσω → subjunctive-type meaning
• μόλις
  • τελειώσω → as soon as I finish

That is why πάρω and τελειώσω may look similar: they belong to the same system.

That mark is called the άνω τελεία in Greek.

It is used as a pause somewhat like an English:

• semicolon
• colon
• strong comma

So in this sentence it simply separates the two parts:

• Μην στενοχωριέσαι τόσο
• θα σε πάρω μόλις τελειώσω

Important: it is not the Greek question mark.

The Greek question mark looks like this:

• ;

So:

• Τι κάνεις; = How are you?

That often surprises English speakers.

Yes. This sentence is addressed to one person informally, so it uses:

• στενοχωριέσαι
• σε

For formal singular or plural you would normally say:

Μην στενοχωριέστε τόσο· θα σας πάρω μόλις τελειώσω.

Changes:

• στενοχωριέσαι → στενοχωριέστε
• σε → σας

So Greek distinguishes between:

• informal singular you
• formal/plural you

English usually does not, which is why this is a common question for learners.