Το άλογο είναι έξω.

Το means the. It is the definite article and it agrees with άλογο in gender, number, and case.

Here, το άλογο means the horse.

A useful grammar point:

• το = the for neuter singular
• άλογο is a neuter singular noun

So the article is not optional here if you mean the horse.

No. Neuter here is grammatical gender, not biological sex.

In Greek, nouns belong to grammatical gender classes:

• masculine
• feminine
• neuter

Άλογο happens to be neuter, even though a real horse can of course be male or female.

So in this sentence, the horse is treated grammatically as it, but that does not tell you anything about the animal’s actual sex.

Άλογο is pronounced roughly AH-lo-gho.

A more careful breakdown:

• ά = stressed a
• λο = lo
• γο = gho

The stress is on the first syllable, shown by the accent mark: ά.

The γ here is not a hard English g. Before ο, it is the Greek sound /ɣ/, often described for learners as a soft gh sound.

Είναι means is here.

It is the third person singular form of the verb είμαι, meaning to be.

So:

• είμαι = I am
• είναι = he/she/it is

In this sentence, είναι links the subject το άλογο with the location έξω.

Είναι is pronounced roughly EE-neh.

More exactly, in Modern Greek it sounds like /ˈine/.

Two spelling points often confuse English speakers:

• ει is pronounced i
• αι is pronounced e

The accent shows that the stress falls on the first syllable: εί.

Because Greek does not need a subject pronoun here.

English often says it is, but Greek can simply say είναι when the subject is already stated or understood.

In this sentence, the subject is already there:

• Το άλογο = the horse

So Greek does not need an extra word for it.

Έξω is an adverb. Here it means outside or out.

It does not change form here, and it is not an adjective agreeing with άλογο. It simply tells you where the horse is.

So the structure is:

• Το άλογο = subject
• είναι = verb
• έξω = adverb of place

Because έξω by itself can mean simply outside.

You use έξω από when you want to say outside of something specific.

Examples:

• Το άλογο είναι έξω. = The horse is outside.
• Το άλογο είναι έξω από το σπίτι. = The horse is outside the house.

So in your sentence, no object is mentioned, so plain έξω is enough.

This word order is the most neutral and straightforward:

• Το άλογο είναι έξω.

Greek word order is often more flexible than English, though different orders can add emphasis.

For example:

• Έξω είναι το άλογο. can sound more emphatic, something like It’s outside that the horse is or The horse is outside with extra focus on outside.

But for a basic statement, Το άλογο είναι έξω is the normal choice.

Yes. In natural English, outside and out can both fit depending on context.

So Το άλογο είναι έξω can mean:

• The horse is outside.
• The horse is out.

The Greek sentence itself does not force a big difference between those two English translations.

It is in the nominative case, because it is the subject of the sentence.

So:

• το = nominative singular neuter article
• άλογο = nominative singular neuter noun

One thing that can confuse learners: for many neuter nouns in Greek, the nominative and accusative singular look the same. So το άλογο can appear in either case depending on the sentence. Here, it is nominative because the horse is doing the role of the subject.

You would usually say:

Ένα άλογο είναι έξω.

Here:

• ένα = a / one for a neuter singular noun
• άλογο = horse

So:

• το άλογο = the horse
• ένα άλογο = a horse

To make it negative, add δεν before the verb:

Το άλογο δεν είναι έξω.
= The horse is not outside.

To turn it into a question, Greek often just uses intonation in speech, and a question mark in writing:

Το άλογο είναι έξω;
= Is the horse outside?

So the basic sentence pattern stays very similar.