V oblasti je jeden dům.

Because the preposition v meaning in requires the locative case when it expresses location.

• base form: oblast = area, region
• after v for location: v oblasti = in the area

So:

• oblast = nominative singular
• v oblasti = locative singular

This is a very common pattern in Czech:

• v domě = in the house
• ve škole = in the school
• v oblasti = in the area

It is locative singular.

The noun oblast is a feminine noun, and after v when talking about being somewhere, Czech uses the locative:

• ta oblast = the area
• v oblasti = in the area

For an English speaker, the important thing is to remember that Czech changes the noun ending after certain prepositions.

Czech usually does not use a separate dummy word like English there in sentences such as there is / there are.

Instead, it simply uses the verb to be:

• je = is

So V oblasti je jeden dům literally looks like:

• In the area is one house

But in natural English, you translate it as:

• There is one house in the area

So the English there has no direct word in this Czech sentence.

Because the subject is singular:

• jeden dům = one house

So Czech uses singular je = is.

Compare:

• V oblasti je jeden dům. = There is one house in the area.
• V oblasti jsou dva domy. = There are two houses in the area.

Jeden means one.

In this sentence, it emphasizes the exact number:

• jeden dům = one house

It is grammatical and natural here, especially if the point is the number.

But Czech can often omit jeden if you just mean a house in a general sense:

• V oblasti je dům. = There is a house in the area.

So:

• dům can mean a house or the house, depending on context
• jeden dům clearly means one house

Usually here it means the number one.

In some contexts, jeden can also mean something like a certain or one in a storytelling sense, but in this sentence the most natural reading is numerical:

• V oblasti je jeden dům. = There is one house in the area.

So a learner should understand it here as exactly one house.

Because dům is the noun that agrees with the verb as the subject of the sentence, so it appears in the nominative singular:

• dům = house

In existential sentences like this, Czech often keeps the thing that exists in the nominative:

• Je tam škola. = There is a school there.
• V oblasti je jeden dům. = There is one house in the area.

So dům stays in its dictionary form here.

Yes, Czech word order is more flexible than English, but different orders change the focus or emphasis.

V oblasti je jeden dům is natural because it starts with the setting/location and then gives the new information.

Very roughly:

• V oblasti je jeden dům. = In the area, there is one house.

Other orders are possible, for example:

• Jeden dům je v oblasti.

But that version sounds more like you are contrasting or emphasizing one house as the topic. In many neutral contexts, V oblasti je jeden dům sounds more natural.

So the chosen order is mainly about information structure, not basic grammar.

Because Czech has no articles.

English says:

• a house
• the house

Czech simply says:

• dům

Whether it means a house, the house, or just house depends on context, word order, and the situation.

That is one reason why jeden can be useful: it makes the meaning clearly one house rather than just a/the house.

Oblast is a fairly general word meaning area, region, zone, or sometimes field/domain, depending on context.

In this sentence, v oblasti most naturally means:

• in the area
• in the region

So oblast is a broad, neutral word. The best English translation depends on context.

A simple approximation is:

• je sounds like ye
• dům sounds roughly like doom, but with a long Czech ů

So the full sentence is approximately:

• v oblasti ye yeden doom

A few details:

• j in Czech is pronounced like English y in yes
• ů is a long u sound
• ě does not appear in this sentence, so there is no special ye/yeh issue beyond je

This is only an approximation, but it is close enough for a beginner.

Yes, je is enough.

Czech often uses být (to be) to express existence, where English uses there is:

• V oblasti je jeden dům. = There is one house in the area.

Czech can use a verb meaning exist, but that would sound different and usually more formal or abstract:

• existuje = exists

For this sentence, je is the normal everyday choice.

Yes.

• V oblasti = in an area / in the area
• V té oblasti = in that area / in the specific area

Adding té makes it more specific. It tells the listener you mean a particular area already known from the context.

So:

• V oblasti je jeden dům. = There is one house in the area.
• V té oblasti je jeden dům. = There is one house in that area.

Mostly yes, but in connected speech it can sound slightly influenced by the following word.

Before oblasti, it is simply v + oblasti:

• v oblasti

In careful speech, you pronounce both clearly. Some Czech prepositions can sound a little smoother in fast speech, but as a learner you should just pronounce it as written.

Also note that Czech sometimes uses ve instead of v for easier pronunciation:

• ve škole
• ve městě

But here v oblasti is the normal form, not ve oblasti.