Η συνάδελφός μου πληκτρολογεί τη διεύθυνση αργά, για να μην κάνει λάθος στον ταχυδρομικό κώδικα.

Because μου is an enclitic word, meaning it leans on the previous word for stress. In Greek, when a word like συνάδελφος is followed by an enclitic, the previous word may receive an extra accent.

So:

• συνάδελφος = colleague
• συνάδελφός μου = my colleague

The extra accent helps show the pronunciation pattern. This is very common with possessive enclitics like μου, σου, του, της.

A similar example is:

• το όνομά μου = my name

Here it is feminine, because the article is Η.

• ο συνάδελφος = the male colleague
• η συνάδελφος = the female colleague

The noun συνάδελφος can refer to either a man or a woman; the article usually makes the gender clear.

So in this sentence, Η συνάδελφός μου means my female colleague.

Because possessive weak forms like μου normally come after the noun in Greek.

So:

• η συνάδελφός μου = my colleague
• το σπίτι μου = my house
• η διεύθυνσή σου = your address

This is one of the most basic word-order differences from English. English puts my before the noun, but Greek often uses a clitic possessive after the noun.

In Modern Greek, the feminine accusative article την often loses its final -ν, becoming τη, depending on the sound that follows.

Here the next word is διεύθυνση, which begins with δ, so τη διεύθυνση is the normal form.

Very roughly:

• την is kept before vowels and certain consonant sounds
• otherwise, it is often shortened to τη

So:

• τη διεύθυνση
• τη φίλη μου
• but την ώρα, την πόρτα

This is a very common spelling and pronunciation issue for learners.

Because it is the direct object of πληκτρολογεί.

The verb πληκτρολογώ / πληκτρολογεί means to type, and the thing being typed is the object. In Greek, direct objects usually go in the accusative case.

So:

• nominative: η διεύθυνση = the address
• accusative: τη διεύθυνση = the address, as an object

That is why the sentence has:

• πληκτρολογεί τη διεύθυνση = she is typing the address

It is the 3rd person singular present tense form of πληκτρολογώ.

So:

• εγώ πληκτρολογώ = I type / I am typing
• εσύ πληκτρολογείς = you type
• αυτή πληκτρολογεί = she types / she is typing

In this sentence, the subject is Η συνάδελφός μου, so the verb must be 3rd person singular: πληκτρολογεί.

Also, Greek present tense can often correspond to either English types or is typing, depending on context.

It is an adverb here.

It tells us how she is typing:

• πληκτρολογεί αργά = she types slowly / she is typing slowly

Compare:

• αργός / αργή / αργό = slow, late (adjective)
• αργά = slowly, late (adverb)

So here αργά modifies the verb πληκτρολογεί, not a noun.

Greek word order is more flexible than English word order. The adverb αργά could appear in different positions, but πληκτρολογεί τη διεύθυνση αργά sounds natural and clear.

Greek often allows movement for emphasis or rhythm, for example:

• Η συνάδελφός μου πληκτρολογεί αργά τη διεύθυνση
• Η συνάδελφός μου τη διεύθυνση την πληκτρολογεί αργά

These are not all equally neutral, but they are possible. The sentence you have is a normal, straightforward order.

για να introduces a purpose clause. It means something like in order to or so that.

So:

• πληκτρολογεί τη διεύθυνση αργά, για να μην κάνει λάθος...
• She types the address slowly, so that she doesn’t make a mistake...

This is a very common Greek structure:

• διαβάζω για να μάθω = I study in order to learn
• βιάζεται για να προλάβει = he is hurrying so that he can make it in time

Because after για να, Greek uses να-type subjunctive structures, and their negative is μην, not δεν.

So:

• δεν is used to negate ordinary statements
• μην is used with να clauses, commands, wishes, fears, and similar structures

Here:

• για να μην κάνει λάθος = so that she does not make a mistake

Compare:

• Δεν κάνει λάθος. = She is not making a mistake / She doesn’t make a mistake.
• Προσέχει για να μην κάνει λάθος. = She is careful so that she doesn’t make a mistake.

Yes. After να or μην, Greek uses the subjunctive construction, but in many verbs the form looks exactly like the present indicative.

So in isolation:

• κάνει can mean she does / she makes

After να / μην:

• να κάνει
• μην κάνει

These are subjunctive constructions, even though the verb form itself looks the same.

So in this sentence, μην κάνει is understood as part of the purpose clause after για να.

Because κάνω λάθος is a very common fixed expression meaning to make a mistake or to be mistaken.

So:

• κάνω λάθος = I make a mistake / I am mistaken
• έκανα λάθος = I made a mistake
• μην κάνει λάθος = so that she doesn’t make a mistake

Greek often uses this expression without an article. You can think of it as an idiom that learners should memorize as a whole chunk.

στον is the contraction of σε + τον.

• σε = in, at, to, on
• τον = the, masculine accusative
• στον = in/to the

So:

• στον ταχυδρομικό κώδικα = in the postal code / on the postal code / with the postal code, depending on context

Greek σε covers several meanings that English expresses with different prepositions, so you should not expect a one-to-one match with in, on, or to.

Because after σε / στον, the noun is in the accusative case.

So:

• nominative: ο ταχυδρομικός κώδικας
• accusative: τον ταχυδρομικό κώδικα

Since the sentence has στον (from σε + τον), the noun must be accusative:

• στον ταχυδρομικό κώδικα

This is a standard masculine noun pattern in Greek.

Because the Greek present tense often covers both:

• simple present: types
• present continuous: is typing

So πληκτρολογεί can mean either:

• she types
• she is typing

The context tells you which is more natural in English. In this sentence, because it describes what she is doing and why, English often prefers is typing. But Greek does not need a separate verb form for that in this case.