Με την κάρτα SIM αγοράζω πακέτο δεδομένων.

Here με means with or using.

So με την κάρτα SIM means with the SIM card or more naturally in English, using the SIM card.

In Greek, με + accusative is often used not only for together with, but also for the means/instrument by which something is done.

Examples:

• γράφω με μολύβι = I write with a pencil
• πληρώνω με κάρτα = I pay by card

So in this sentence, the SIM card is the means used for the purchase.

Because με takes the accusative case, not the nominative.

The noun κάρτα is feminine singular:

• η κάρτα = nominative, the card
• την κάρτα = accusative, the card

So after με, you need:

• με την κάρτα

This is very common in Greek:

• με τον φίλο μου = with my friend
• με τη μητέρα μου = with my mother

Because SIM is treated as an indeclinable foreign abbreviation here.

Greek often keeps brand names, abbreviations, and some foreign words unchanged, while the Greek noun before them carries the grammar.

So:

• η κάρτα SIM
• την κάρτα SIM

Only κάρτα changes. SIM stays the same.

This is similar to how English might say the SIM card—only card behaves like the main noun.

Αγοράζω is the 1st person singular present tense of the verb αγοράζω, meaning I buy or I am buying.

So:

• αγοράζω = I buy / I’m buying

Greek present tense can cover both:

• a general action: I buy
• an action happening now: I’m buying

The exact meaning depends on context.

Related forms:

• αγοράζεις = you buy
• αγοράζει = he/she/it buys
• αγοράζουμε = we buy

Because Greek usually does not need to state the subject pronoun when the verb ending already shows who the subject is.

In αγοράζω, the ending -ω tells you the subject is I.

So:

• αγοράζω = I buy
• εγώ αγοράζω = I buy with extra emphasis on I

Greek often leaves pronouns out unless they are needed for contrast, emphasis, or clarity.

For example:

• Αγοράζω πακέτο δεδομένων. = I buy a data package.
• Εγώ αγοράζω, όχι εσύ. = I’m buying, not you.

Greek can leave the object without an article, especially in more general, compact, or informational language.

So:

• αγοράζω πακέτο δεδομένων = I buy a data package / I’m buying a data package

In everyday speech, you might also hear:

• αγοράζω ένα πακέτο δεδομένων = I buy a data package / one data package

Adding ένα makes it clearly indefinite and often sounds more like normal conversational English a data package.

Without ένα, the phrase can sound a bit more general, neutral, or concise—something you might see in instructions, menus, or service descriptions.

Because δεδομένων is the genitive plural of δεδομένα.

The expression πακέτο δεδομένων literally means:

• package of data

This is a very common Greek structure:

• noun + genitive noun

So:

• πακέτο δεδομένων = data package
• literally: package of data

Here are the forms:

• τα δεδομένα = the data (nominative/accusative plural)
• των δεδομένων = of the data (genitive plural)

Even without the article, the noun stays in the genitive:

• πακέτο δεδομένων

It is the accusative singular, because it is the direct object of αγοράζω.

You buy what?

• πακέτο δεδομένων

However, for many neuter nouns in Greek, the nominative and accusative singular look exactly the same.

So:

• το πακέτο = nominative or accusative singular, depending on its role in the sentence

That is why it looks like the dictionary form even though it is functioning as the object.

Yes, it is normal, but Greek word order is more flexible than English.

This sentence starts with:

• Με την κάρτα SIM = With the SIM card / Using the SIM card

Then comes the verb:

• αγοράζω

Then the object:

• πακέτο δεδομένων

A more neutral order in some contexts could also be:

• Αγοράζω πακέτο δεδομένων με την κάρτα SIM.

Both are grammatical. The version with με την κάρτα SIM first gives that part a bit more prominence, as if setting the frame: Using the SIM card, I buy a data package.

Greek often moves elements around for focus, emphasis, or style.

Not necessarily. In this sentence, it most naturally means using the SIM card or by means of the SIM card.

The preposition με can mean different things depending on context:

• with = together with
• with/by using = by means of

Here, because the verb is αγοράζω and the phrase refers to κάρτα SIM, the most likely meaning is instrumental: using the SIM card.

So it does not usually mean that the SIM card and the package are being bought together as a bundle. It means the SIM card is connected with how the package is purchased.

Yes, it is understandable and grammatical, especially in a service, telecom, or instructional context.

That said, in everyday conversation, a speaker might more often say:

• Με την κάρτα SIM αγοράζω ένα πακέτο δεδομένων.
• Αγοράζω πακέτο δεδομένων με την κάρτα SIM.
• Μπορώ να αγοράσω πακέτο δεδομένων με την κάρτα SIM.

Adding ένα can make it sound more natural if you mean a data package in ordinary speech.

So the original sentence is fine, but depending on context, a Greek speaker might choose a slightly fuller version.