Learn Hardcore Greek: Ένα καινούριο κτίριο χτίζεται δίπλα στο πανεπιστήμιο. - A new building is being built next to the university.

κτίριο = building
- It is neuter gender, singular.
καινούριο = new
- Adjective in neuter, singular, to agree with κτίριο.
ένα = a / one
- Indefinite article, neuter singular, also agreeing with κτίριο.

In Greek, article + adjective + noun must match in:

gender (here: neuter)
number (here: singular)
case (here: nominative, the subject of the sentence)

So you get:
(ένα) [indef. article, neuter nom. sg.]
(καινούριο) [adj., neuter nom. sg.]
(κτίριο) [noun, neuter nom. sg.]

What’s the difference between καινούριο and νέο for “new”? Could I say ένα νέο κτίριο?

Both καινούριο and νέο often mean new, and ένα νέο κτίριο is perfectly correct.

Nuances (not absolute, but common):

καινούριο: emphasizes brand new / recently acquired / unused before.
- e.g. a newly built house, a new phone you just bought.
νέο: more general new / recent, often in a more formal or abstract sense.
- e.g. νέα τεχνολογία (new technology), νέος νόμος (new law).

In this sentence, καινούριο κτίριο nicely emphasizes that the building is newly built, so it fits very well. But νέο κτίριο would also be understood and acceptable.

Why is the verb χτίζεται and not χτίζει? How does this express “is being built”?

χτίζει = he/she/it builds (active voice)
χτίζεται = he/she/it is being built (middle/passive voice)

Greek uses the middle/passive voice to express what English usually says with “is being …-ed”.

Verb: χτίζω = to build
3rd person singular, present, middle/passive: χτίζεται
→ it is being built / it is built

So:

Ένα καινούριο κτίριο χτίζει
= A new building builds (nonsense)
Ένα καινούριο κτίριο χτίζεται
= A new building is being built

That’s why χτίζεται is used: the building is the thing undergoing the action.

How is χτίζεται formed from χτίζω?

The verb is χτίζω (to build).

Present tense (indicative):

(εγώ) χτίζω – I build
(εσύ) χτίζεις – you build
(αυτός/αυτή/αυτό) χτίζει – he/she/it builds
(εμείς) χτίζουμε – we build
(εσείς) χτίζετε – you (pl/formal) build
(αυτοί/αυτές/αυτά) χτίζουν(ε) – they build

Middle/passive present:

(εγώ) χτίζομαι – I am being built
(εσύ) χτίζεσαι – you are being built
(αυτός/αυτή/αυτό) χτίζεται – he/she/it is being built
(εμείς) χτιζόμαστε
(εσείς) χτίζεστε
(αυτοί/ές/ά) χτίζονται

So in the sentence the subject is ένα καινούριο κτίριο, and the correct form is χτίζεται (3rd person singular, middle/passive).

What exactly does δίπλα στο mean? Is it the same as “next to” or “near”?

δίπλα στο literally means next to / beside the.

δίπλα = next to, beside
στο = σε + το (in/at/to + the), neuter singular

So δίπλα στο πανεπιστήμιο = next to the university.

Comparison:

δίπλα στο → normally very close / adjacent / right next to
κοντά στο → near the, but not necessarily immediately beside

So δίπλα στο πανεπιστήμιο suggests the building is right by the university, or at least very close.

What is στο? Why not just σε το πανεπιστήμιο?

In Greek, σε (in/at/to) often contracts with the definite articles:

σε + το → στο
σε + τον → στον
σε + τη(ν) → στη(ν)
σε + τους → στους
σε + τις → στις
σε + τα → στα

Here:

σε = in / at / to
το πανεπιστήμιο = the university (neuter, singular)

So σε το πανεπιστήμιο almost always becomes στο πανεπιστήμιο in real Greek.

Why is it πανεπιστήμιο and not some other gender? Do article and preposition agree with it?

πανεπιστήμιο (university) is a neuter noun in Greek.

Its nominative singular form is το πανεπιστήμιο.

In the phrase:

στο πανεπιστήμιο = σε + το πανεπιστήμιο

The article το is neuter singular, agreeing with πανεπιστήμιο. The preposition σε itself doesn’t change; it just contracts with the article into στο.

So gender/number agreement here is simply:

το (neuter, singular) → matches πανεπιστήμιο (neuter, singular).

Can I change the word order, for example: Δίπλα στο πανεπιστήμιο χτίζεται ένα καινούριο κτίριο?

Yes. Greek word order is fairly flexible, especially for emphasis.

All of these are grammatically correct and mean essentially the same thing:

Ένα καινούριο κτίριο χτίζεται δίπλα στο πανεπιστήμιο.
→ neutral, subject-first.
Δίπλα στο πανεπιστήμιο χτίζεται ένα καινούριο κτίριο.
→ emphasizes the location first.
Δίπλα στο πανεπιστήμιο ένα καινούριο κτίριο χτίζεται.
→ still understandable, slightly marked style.

As long as the endings show who is doing what to whom, Greek allows some reordering to highlight different parts of the sentence.

Why is there no word for “is” like είναι? In English we say “is being built”.

English uses “to be” + being + past participle:
is being built

Greek normally expresses this with a single verb in the middle/passive voice, not with είναι:

χτίζεται = is being built / is built

So:

Ένα καινούριο κτίριο χτίζεται
literally: A new building is-built
functionally: A new building is being built.

You could say είναι χτισμένο (“is built”) but that means it is already built / it stands there finished, not the process.

Why is it κτίριο but χτίζεται? Why κτ vs χτ?

Modern Greek has both:

χτίζω and κτίζω → to build
κτίριο and κτήριο → building

In practice today:

χτίζω is more common in everyday speech.
κτίζω is more formal / learned (related to ancient κτίζω).
For the noun, κτίριο is the usual modern spelling, though κτήριο also exists.

So the mixture κτίριο / χτίζεται is very normal:

Ένα καινούριο κτίριο χτίζεται…

You could also see more formal variants like:

Ένα καινούριο κτήριο κτίζεται…

but that would sound a bit more bookish or formal.

Does the Greek present χτίζεται mean specifically “is being built” (continuous), or can it also mean “is built” in general?

Greek present tense often covers both:

ongoing action (is being built now)
habitual / general action (is built, as a general fact)

So χτίζεται can, depending on context, be understood as:

is being built (right now, process)
is built (whenever this happens, as a regular procedure)

In this sentence, with ένα καινούριο κτίριο and no time adverb, most listeners will naturally interpret it as:

A new building is being built next to the university (these days / currently).