Το διαμέρισμα απέναντι είναι άδειο τώρα, αλλά νομίζω ότι σύντομα θα έρθει μια καινούρια ενοικιάστρια.

Both are possible, but they are used a little differently.

• το διαμέρισμα απέναντι = the apartment opposite / across
• το απέναντι διαμέρισμα = the opposite apartment

In this sentence, απέναντι comes after the noun and works almost like the one across/opposite. This is a very common and natural way to say it in Greek.

So το διαμέρισμα απέναντι is extremely idiomatic when talking about a nearby apartment that is across from the speaker.

Here απέναντι means opposite, across, or across from here/from us.

It can function as:

• an adverb: Είναι απέναντι. = It’s opposite/across.
• a kind of post-position after a noun: το σπίτι απέναντι = the house across the way

So in this sentence, το διαμέρισμα απέναντι means the apartment across from us / opposite.

Because διαμέρισμα is a neuter noun.

Greek adjectives must agree with the noun they describe in:

• gender
• number
• case

So:

• άδειος = masculine
• άδεια = feminine
• άδειο = neuter

Since το διαμέρισμα is neuter singular, the adjective must also be neuter singular:

• Το διαμέρισμα είναι άδειο. = The apartment is empty.

Because Greek often does not need an explicit subject pronoun when the subject is already clear.

In English, you say:

• It is empty now.

In Greek, the subject is already known from το διαμέρισμα, so Greek simply says:

• Το διαμέρισμα ... είναι άδειο τώρα.

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

Τώρα means now.

It tells us that the apartment is empty at the present time:

• είναι άδειο τώρα = is empty now

Its position is flexible. Greek word order is freer than English, so you could also hear:

• Τώρα είναι άδειο
• Είναι τώρα άδειο

But είναι άδειο τώρα sounds very natural.

νομίζω means I think and ότι means that.

So:

• νομίζω ότι... = I think that...

Greek often uses ότι after verbs of thinking, saying, knowing, etc.

You may also hear:

• νομίζω πως...

Both ότι and πως can mean that in this kind of sentence. In everyday speech, both are common.

This is a very important Greek pattern.

Greek forms the future with:

• θα
  • a verb form

Here:

• θα έρθει = will come

The verb έρχομαι has:

• imperfective future: θα έρχεται = will be coming / will come repeatedly in some contexts
• perfective future: θα έρθει = will come as a single completed event

In this sentence, the speaker means one future event:

• a new tenant will arrive / move in

So Greek uses the perfective form:

• θα έρθει

This is one of the most common patterns in Greek:

• θα γράψω = I will write
• θα φύγει = he/she will leave
• θα έρθει = he/she will come

Yes. Literally it means:

• a new female tenant will come

But in this context, the natural English sense is often:

• a new tenant will move in
• a new tenant will arrive soon

Greek often uses έρχομαι in contexts where English might prefer move in, arrive, or come depending on the situation.

So the Greek is natural, even if the most natural English translation may vary.

Because ενοικιάστρια is a feminine singular noun.

So the article and adjective must match it:

• μια = a / one, feminine singular
• καινούρια = new, feminine singular
• ενοικιάστρια = female tenant/renter

Everything agrees in gender and number.

If it were masculine, you would have:

• ένας καινούριος ενοικιαστής = a new male tenant

They are basically the same word.

• μια is the very common everyday spelling
• μία can be used when you want to stress one more clearly, or in more careful writing

In many modern texts, μια is the normal form.

So here:

• μια καινούρια ενοικιάστρια = a new tenant

There is no special difference in meaning here.

ενοικιάστρια means female tenant or female renter.

Related forms:

• ενοικιαστής = male tenant
• ενοικιάστρια = female tenant
• ενοίκιο = rent

So this word refers to the person renting the apartment, not the owner.

Because in Greek, adjectives often come before the noun:

• μια καινούρια ενοικιάστρια = a new tenant

This is the most straightforward and common position here.

Greek adjectives can sometimes come after the noun too, but that may sound more marked or stylistically different depending on the context. For a basic description like this, putting the adjective before the noun is the normal choice.

Yes, often it could.

• καινούριος / καινούρια / καινούριο = new
• νέος / νέα / νέο = new

In many contexts they overlap. So:

• μια καινούρια ενοικιάστρια
• μια νέα ενοικιάστρια

Both can mean a new tenant.

Very roughly:

• καινούριος often feels like brand-new or newly introduced
• νέος can also mean new, but it can additionally mean young in other contexts

Here, καινούρια avoids any possible ambiguity with young, so it is very natural.

σύντομα means soon.

Greek adverbs are fairly flexible in position. Here:

• σύντομα θα έρθει = will come soon

This sounds natural and neutral.

You could also hear:

• θα έρθει σύντομα

Both are correct. The version in the sentence places a little focus on the time idea soon.

Yes. αλλά is the standard word for but.

It links the two contrasting ideas:

• The apartment is empty now
• but I think a new tenant will come soon

So:

• ..., αλλά νομίζω ότι ... = ..., but I think that ...

Because αλλά introduces a new clause and contrasts with what came before.

Greek punctuation often works similarly to English here:

• statement 1, but statement 2

So the comma helps separate:

• Το διαμέρισμα απέναντι είναι άδειο τώρα from
• αλλά νομίζω ότι σύντομα θα έρθει μια καινούρια ενοικιάστρια

Yes, very natural.

It sounds like something a person might say in conversation about a neighboring apartment. The wording is clear and idiomatic:

• το διαμέρισμα απέναντι = very natural
• είναι άδειο τώρα = normal everyday Greek
• νομίζω ότι σύντομα θα έρθει... = natural way to express a guess or expectation

The only thing to note is that in English you might translate the last part more naturally as a new tenant will move in soon, even though the Greek literally uses come.