Köpek evin arkasında uyuyor.

Because Turkish is saying something like the back of the house.

To build that, Turkish uses:

• ev = house
• evin = of the house / the house’s

The ending -in is the genitive suffix. So evin shows that house is the possessor in the phrase evin arkası = the back of the house.

Arkasında has several parts:

• arka = back, rear
• -sı = a possessive ending here used in the construction evin arkası = the back of the house
• -nda = in/on/at, the locative ending, with a buffer n

So:

• evin arkası = the back of the house
• evin arkasında = at the back of the house / behind the house

This is a very common Turkish pattern for location expressions.

Because Turkish often expresses spatial relationships through a possessed noun.

So instead of using a completely separate word for behind, Turkish often says something more literal like:

• evin arkası = the house’s back
• evin arkasında = at the house’s back

In natural English, that becomes behind the house or at the back of the house.

So the possessive ending is normal Turkish grammar here, even if English does not show it the same way.

Turkish has no articles like English a/an/the.

That means:

• köpek can mean a dog or the dog
• ev can mean a house or the house

Which meaning is intended depends on context.

If you want to make a dog more explicit, you can often use bir:

• Bir köpek evin arkasında uyuyor. = A dog is sleeping behind the house.

Without bir, köpek is more neutral and context decides.

Because köpek is the subject of the sentence, and the basic subject form in Turkish is usually unmarked. This is often called the nominative form.

So:

• köpek = dog / the dog

No extra suffix is needed here.

By contrast, Turkish often marks definite direct objects with the accusative, but köpek is not an object in this sentence—it is the one doing the sleeping.

Uyuyor is the present continuous (also called the progressive).

It comes from:

• uyumak = to sleep
• verb stem: uyu-
• -yor = ongoing action

So uyuyor means:

• is sleeping
• sometimes, depending on context, simply sleeps

In this sentence, the most natural sense is is sleeping.

Because Turkish default word order is usually Subject – Object/Other elements – Verb.

So:

• Köpek = subject
• evin arkasında = location
• uyuyor = verb

This gives the normal neutral order:

• Köpek evin arkasında uyuyor.

English usually puts the verb earlier, but Turkish commonly saves the verb for the end.

Yes. Turkish word order is flexible, but changing it usually changes emphasis or focus, not the basic meaning.

For example:

• Köpek evin arkasında uyuyor. = neutral
• Evin arkasında köpek uyuyor. = puts more focus on behind the house
• Uyuyor köpek evin arkasında. = possible in special contexts, but less neutral

So the original sentence is the most straightforward, standard way to say it.

That n is a buffer consonant.

Here is the structure:

• arka
• arka-sı = its back / the back of it
• arka-sı-nda = at its back

After certain possessive endings, Turkish often inserts n before another suffix. That is why you get -nda here instead of just -da directly attached.

So arkasında is not random—it follows a regular pattern.

This is because the locative suffix changes form according to Turkish sound rules.

The locative has four common forms:

• -da
• -de
• -ta
• -te

Which one appears depends on:

1. vowel harmony
2. whether the preceding consonant is voiced or voiceless

In arkasında, the correct form is -da, and because of the buffer consonant n, it appears as -nda.

So:

• arka-sı-nda

This is just the normal harmonic form for this word.

Two sounds may feel unfamiliar to English speakers:

• ö in köpek: a front rounded vowel, similar to German ö or French eu in some words
• ı in arkasında: a vowel with no exact English equivalent; it is a close back unrounded vowel

A rough guide:

• köpek sounds approximately like KER-pek with rounded lips on the first vowel
• ı is not ee and not uh; it is a flatter, more central/back sound

Also:

• uyuyor is pronounced roughly oo-YOO-yor

Listening and repeating is especially important for these vowels, because Turkish distinguishes them very clearly.

Yes, but arkasında is a very common and natural choice.

Related possibilities include:

• evin arkasında = behind the house / at the back of the house
• evin arka tarafında = at the back side of the house

The sentence you have is simple, standard, and very idiomatic. It is exactly the kind of structure learners should get used to.