Μεθαύριο θα πάω ξανά στο παντοπωλείο, γιατί θέλω να εξοικονομήσω χρόνο και να αγοράσω όλα μαζί.

Yes, Μεθαύριο is one word, and it means the day after tomorrow.

It is built from older elements meaning something like after tomorrow, but in Modern Greek you simply learn it as a fixed everyday word, just like:

• σήμερα = today
• αύριο = tomorrow
• μεθαύριο = the day after tomorrow

So in this sentence, it sets the time right at the beginning.

In Modern Greek, the future is usually formed with θα + verb.

So:

• πάω = I go / I am going
• θα πάω = I will go

Greek does not have a separate future verb ending like some languages do. Instead, θα is the marker that gives the future meaning.

This is mainly about aspect.

In this sentence, the speaker is talking about one whole trip to the shop in the future, so Greek uses the perfective idea:

• θα πάω = I will go, as a single complete action

If you used θα πηγαίνω, it would usually sound more like:

• I will be going
• I will go regularly
• I will keep going

So θα πάω is the natural choice for a one-time planned visit.

Ξανά means again.

So θα πάω ξανά means I will go again.

Its position is flexible, but the version in the sentence is very natural. Greek often allows adverbs like ξανά to move around a bit depending on emphasis. For example, you may also hear:

• θα ξαναπάω στο παντοπωλείο

That is also natural and very common. The meaning is basically the same, though the emphasis shifts slightly.

Because στο is the contracted form of σε + το.

So:

• σε το becomes στο

This is standard Greek contraction. Similar forms are:

• στο = to/in/at the, neuter singular
• στον = to/in/at the, masculine singular
• στη or στην = to/in/at the, feminine singular
• στα = to/in/at the, plural

In this sentence, παντοπωλείο is neuter, so στο παντοπωλείο is correct.

Παντοπωλείο is a grocery store, provisions shop, or general food shop.

Depending on context, it may sound a bit more traditional than σούπερ μάρκετ. A learner might translate it as grocery store in most cases.

So the sentence is talking about going to a food shop to buy things.

Yes. Γιατί can mean both:

• why?
• because

You understand which meaning it has from the sentence structure and intonation.

Here it introduces a reason:

• γιατί θέλω... = because I want...

If it were a question, it would mean why?, as in:

• Γιατί πας; = Why are you going?

This dual use is very common in Greek.

Because Modern Greek does not normally use an infinitive the way English does.

English says:

• I want to save
• I want to buy

Greek uses:

• θέλω να εξοικονομήσω
• θέλω να αγοράσω

The word να introduces the following verb clause. English learners often think of it as corresponding to to, but grammatically it is not an infinitive marker in the same way. It is part of a different Greek structure, often called the subjunctive construction.

So a very common pattern is:

• θέλω να + verb = I want to + verb

Again, this is about aspect.

After να, Greek often chooses between:

• a perfective form for a complete action
• an imperfective form for an ongoing, repeated, or habitual action

Here the speaker means:

• save time as a complete result
• buy everything in one go

So Greek uses the perfective forms:

• να εξοικονομήσω
• να αγοράσω

If you used imperfective forms such as να εξοικονομώ or να αγοράζω, it would sound more like an ongoing or habitual activity, which does not fit this sentence as well.

Because in standard Greek, when two verbs are coordinated after θέλω, it is very natural to repeat να before the second one.

So:

• θέλω να εξοικονομήσω χρόνο και να αγοράσω όλα μαζί

This is clearer and more standard than leaving the second να out.

English does not repeat to as often in the same way, so this can feel unusual to learners. But in Greek, να... και να... is a very normal pattern.

Because Greek often leaves out the article with abstract or general ideas when speaking in a broad sense.

So:

• να εξοικονομήσω χρόνο = to save time

This means time in general, not a specific identified block of time.

If you added an article, such as τον χρόνο, it would usually sound more specific, and in this sentence that is not the intended idea.

Literally, όλα μαζί means all together.

In this sentence, the natural meaning is:

• everything at once
• all in one go
• all in one trip

Here όλα is neuter plural and refers to the things the speaker wants to buy. Greek often uses όλα this way when the noun is understood from context.

Because the clause after γιατί gives the reason for the main clause.

Greek usually separates that kind of explanatory clause with a comma:

• Μεθαύριο θα πάω ξανά στο παντοπωλείο, γιατί θέλω...

This is standard punctuation and helps make the structure of the sentence clear.