Moj auto je ispred kuće, a pas je iza kuće.

Because moj has to agree with the grammatical gender of auto.

Even though auto ends in -o, it is commonly treated as masculine in Serbian, largely because it is a shortened form of automobil, which is masculine. So you say:

• moj auto
• ovaj auto
• taj auto

This is one of those places where the ending does not tell the whole story.

Because both ispred and iza require the genitive case.

The basic dictionary form is kuća.
Its genitive singular form is kuće.

So:

• ispred kuće = in front of the house
• iza kuće = behind the house

This is a very common pattern in Serbian: certain prepositions always trigger a specific case, and here that case is the genitive.

In this sentence, a connects two clauses with a slight sense of contrast or comparison.

So a often means something like:

• and
• while
• whereas
• but in a very mild sense

Here it sounds natural because the sentence is comparing two locations:

• Moj auto je ispred kuće
• a pas je iza kuće

If you used i, it would sound more like a simple addition. A is better when the second part shifts attention a little or sets up a contrast.

Je is the third person singular present form of biti, meaning is.

So:

• Moj auto je ispred kuće = My car is in front of the house
• pas je iza kuće = the dog is behind the house

It appears twice because there are really two separate clauses, and each one has its own verb.

Also, je is a clitic, which means it usually stands in the second position in its clause. That is why you get:

• Moj auto je ...
• pas je ...

not normally Moj auto ispred kuće je.

Because Serbian clitics such as je usually come in the second position of the clause, after the first whole unit, not necessarily after the first single word.

Here, Moj auto acts as one phrase, so je comes after that phrase:

• Moj auto | je | ispred kuće

This is very normal Serbian word order.

Yes. Pred kućom can also mean in front of the house.

So both of these are possible:

• ispred kuće
• pred kućom

The difference is roughly this:

• ispred + genitive is a very common, explicit way to say in front of
• pred + instrumental is also correct, but it can feel a bit broader depending on context

In many everyday situations, both are natural. In this sentence, ispred kuće is perfectly standard.

They are in the nominative case because they are the subjects of the two clauses.

• Moj auto = subject of je ispred kuće
• pas = subject of je iza kuće

You can also see agreement in moj, which is in the form that matches nominative singular masculine.

Because Serbian does not have articles like English the and a/an.

So Serbian simply says:

• moj auto
• pas
• kuće

Whether something is definite or indefinite is usually understood from context, word order, or the situation.

That is why English needs the house or a dog, but Serbian does not use separate article words.

Yes, if the context already makes it clear whose car it is.

For example:

• Auto je ispred kuće = The car is in front of the house

But if you want to be specific and say my car, then moj should stay:

• Moj auto je ispred kuće

So moj is not grammatically required just because Serbian likes possessives; it is there because the speaker wants to identify the car as mine.

The word kuće is pronounced approximately like KOO-cheh, but with a softer sound than English ch in church.

A few pronunciation tips:

• ku- sounds like koo
• ć is a soft Serbian consonant, softer than č
• -e is clearly pronounced, not silent

So kuće is roughly KOO-će.

If you are an English speaker, the main thing to remember is that ć should sound softer and lighter than a hard English ch.