Learn Hardcore Czech: Tento dům má jen jedno patro.

Tento means this and is a more neutral / slightly formal written form. It’s a demonstrative adjective that must agree with the noun in gender, number, and case.

Tento dům = this house (masculine inanimate, singular, nominative)
Tenhle dům = also this house, but more colloquial / spoken
Tohle on its own usually means this (thing) as a standalone pronoun, not followed by a noun:
- Tohle je můj dům. = This is my house.

In a simple, neutral written sentence like Tento dům má jen jedno patro, Tento is perfectly standard. In everyday speech you’re more likely to hear Tenhle dům má jen jedno patro.

Why is dům in this form and not changed for case? Is it nominative?

Yes. Dům is in the nominative singular because it is the subject of the sentence.

Kdo / co má jen jedno patro? – Tento dům.
Subject in Czech normally appears in nominative.

Other important forms of dům:

Nominative singular: dům (the subject, as here)
Genitive singular: domu (without the house = bez domu)
Locative singular: v domě (in the house)

So the unchanged form dům here is exactly what we expect for a subject.

What does má mean exactly, and why do we use mít here instead of some form of být (to be)?

Má is the 3rd person singular present of mít = to have. So literally:

Tento dům má jen jedno patro. = This house has only one floor.

Czech often uses mít to express possession or inherent properties:

Dům má zahradu. – The house has a garden.
Dům má tři okna. – The house has three windows.

You could also express a similar idea with být in a different structure:

V tomto domě je jen jedno patro. – There is only one floor in this house.

But that changes the structure (and focus) from “The house has…” to “There is… in the house”. Both are grammatical; the sentence you gave uses mít for simple possession.

What is the difference between jen, jenom, and pouze? Can I replace jen here?

All three can mean only, but with slightly different feel:

jen – very common, slightly shorter and informal, totally fine in speech and most writing
jenom – basically the same as jen, a bit more colloquial / emphatic in speech
pouze – more formal / bookish; often used in written texts, instructions, official language

In your sentence, all of these are acceptable:

Tento dům má jen jedno patro.
Tento dům má jenom jedno patro.
Tento dům má pouze jedno patro.

The meaning is the same; the main difference is style and rhythm. Jen is the most neutral everyday choice.

Why is it jedno patro and not jeden patro or jedna patro?

Because jedno has to agree with the grammatical gender of patro.

patro is a neuter noun.
The numeral one in Czech has different forms for different genders:
- Masculine animate: jeden (e.g. jeden člověk – one person)
- Masculine inanimate: usually also jeden (e.g. jeden dům – one house)
- Feminine: jedna (e.g. jedna ulice – one street)
- Neuter: jedno (e.g. jedno patro – one floor)

So:

jeden dům (house = masc. inanimate)
jedna ulice (street = feminine)
jedno patro (floor = neuter)

Jeden patro or jedna patro would be grammatically wrong.

What exactly does patro mean? Is it like floor or storey, and how do Czechs count them?

Patro means floor / storey of a building.

Very important: Czech counting of floors differs from British English:

přízemí = ground floor
první patro = the floor above the ground floor
druhé patro = the second floor above the ground floor, etc.

So, comparing:

Czech první patro ≈ British English first floor
Czech první patro ≈ American English second floor

In your sentence:

Tento dům má jen jedno patro.
Literally: This house has only one floor / storey.
Typically this implies: ground floor plus one patro (first floor above ground), or context may vary. Many speakers use patro for the level above ground; if they mean absolutely only ground level, they might specify jen přízemí.

Another word: poschodí can also mean floor/storey, but patro is more common in everyday Czech for houses and buildings.

Can the word order change? For example, can I say Tento dům má pouze jedno patro or Jen jedno patro má tento dům?

Yes, Czech word order is flexible and is used to highlight what is new or important information.

All of these are grammatical:

Tento dům má jen jedno patro.
– Neutral, standard. Focus is balanced; we simply state how many floors it has.
Tento dům má pouze jedno patro.
– Same structure; pouze is just a more formal synonym of jen.
Jen jedno patro má tento dům.
– More unusual / emphatic. Emphasizes the small number: Only one floor is what this house has. Could sound stylistically marked or poetic / contrastive, e.g. compared to other houses.
Tento dům má jedno patro jen.
– This is possible but sounds strange or very marked; jen usually goes before the element it limits.

So the original word order is the most natural, neutral one for everyday use.

Can I drop Tento and just say Dům má jen jedno patro?

Yes, that is possible and grammatical. Then it simply means:

Dům má jen jedno patro. – The house has only one floor.

Differences:

Tento dům = this house (a specific one near us or obvious from context)
Dům without a demonstrative is closer to the house in English; context decides which house.

You add Tento (or Tenhle) when you want to point the house out as this particular one. Without it, you rely more on previous context to identify the house.

How do you pronounce Tento dům má jen jedno patro? Any tricky sounds for an English speaker?

Approximate pronunciation (IPA):

Tento – [ˈtɛntɔ]
dům – [ˈduːm] (long ú sound)
má – [ˈmaː] (long á)
jen – [ˈjɛn] (“je” like ye in yes)
jedno – [ˈjɛdnɔ]
patro – [ˈpatrɔ]

Stress in Czech is almost always on the first syllable of each word:

TEn-to DŮM MÁ JEN JED-no PA-tro

Things to watch:

Long vowels ú/ů and á are really longer in duration; they can distinguish meaning.
Czech r is a tap or trilled, not like English r. In patro, it’s a quick tap [r].
The consonant clusters are simpler here; the main challenge is getting the vowel length and word stress right.

How would I say This house has three floors or five floors? Does patro change?

Yes, patro changes form after numbers. The most common pattern:

jedno patro – one floor (neuter singular)
dvě patra – two floors
tři patra – three floors
čtyři patra – four floors
pět pater – five floors
šest pater – six floors, etc.

Examples with your structure:

Tento dům má dvě patra. – This house has two floors.
Tento dům má tři patra. – This house has three floors.
Tento dům má pět pater. – This house has five floors.

Notice the switch from patra to pater starting with pět (5). That’s because in Czech, numbers 5 and higher usually trigger the genitive plural form of the noun (pater is genitive plural of patro).