Βάλε τα βιβλία σε έναν σωρό.

Βάλε is the singular informal imperative of βάζω (to put).

A few useful points:

• It is used when speaking to one person.
• It is the perfective/aorist imperative, so it usually refers to one complete action: Put ...
• That is why it sounds natural here: the speaker wants the books to end up in a pile.

You may notice that the verb changes stem:

• βάζω = I put / I am putting
• βάλε = put!

That stem change is normal for this verb.

τα βιβλία means the books.

Breakdown:

• τα = the for neuter plural
• βιβλία = plural of βιβλίο (book)

Here it is the direct object of the verb, because these are the things being put somewhere.

Also, with many neuter nouns in Greek, the nominative plural and accusative plural look the same, so τα βιβλία can look the same whether it is a subject or an object. In this sentence, it is clearly the object because of the verb Βάλε.

Because σε is followed by the accusative case in Modern Greek.

So both words after σε must be in the accusative:

• dictionary form: ένας σωρός = a pile
• after σε: σε έναν σωρό

Changes:

• ένας → έναν
• σωρός → σωρό

So σε έναν σωρό is the correct form after σε.

Greek σε can cover several ideas that English separates:

• in
• into
• to
• sometimes on/onto, depending on context

Here, because the verb is βάζω (put), σε has the sense of into / in.

So the idea is:

• Put the books into a pile
• or more naturally in English, Put the books in a pile

Greek often uses the same preposition where English chooses between in and into.

It can mean either, depending on context.

In Greek, the same word serves as:

• the indefinite article (a/an)
• the number one

So here έναν σωρό usually just means a pile.

If the speaker strongly emphasizes έναν, it could mean one pile specifically, as opposed to several piles. But in an ordinary sentence like this, English usually translates it simply as a pile.

Yes, you may hear σε ένα σωρό in everyday speech.

Why?

• The full masculine accusative form is έναν
• In Modern Greek, the final -ν is sometimes dropped before certain consonants in casual usage

So:

• more careful / teaching form: σε έναν σωρό
• very common spoken variant: σε ένα σωρό

For a learner, σε έναν σωρό is the clearest form to learn, because it shows the grammar more transparently.

The difference is who you are talking to.

• Βάλε = say it to one person, informally
• Βάλτε = say it to more than one person, or to one person politely

So:

• Βάλε τα βιβλία σε έναν σωρό. = to one person
• Βάλτε τα βιβλία σε έναν σωρό. = to a group, or polite singular

This is a very common distinction in Greek imperatives.

Because Greek imperatives also show aspect.

• Βάλε = do it / put them as one complete action
• βάζε = keep putting / put repeatedly / be putting

In this sentence, the speaker wants a finished result: the books should end up in a pile. So Βάλε is the natural choice.

A form like βάζε would sound more like:

• keep putting them in a pile
• put them there regularly
• continue the action

So Βάλε fits much better here.

No, Greek word order is more flexible than English word order.

Βάλε τα βιβλία σε έναν σωρό. is a neutral, natural order.

But Greek can move parts around for emphasis, for example:

• Βάλε σε έναν σωρό τα βιβλία.
• Τα βιβλία βάλε σε έναν σωρό.

The basic meaning stays the same, but the emphasis changes.

For learners, the original order is a very good default:

• verb first
• then object
• then the place/result phrase

A simple pronunciation guide is:

VA-le ta vee-VLEE-a se EN-an so-RO

Stress:

• Βά-λε
• βι-βλί-α
• έ-ναν
• σω-ρό

A few sound notes:

• β sounds like English v
• σε sounds like seh
• βι sounds like vee
• σωρό ends with a stressed -RO

So the rhythm is:

VA-le ta vee-VLEE-a se EN-an so-RO