Learn Hardcore Czech: Rychlý autobus je dobrý pro moji rodinu.

Which one is meant depends entirely on context, not on the grammar. If you’re talking about a specific bus everyone already knows about, listeners will understand it as “the fast bus”. If you’re speaking in general, it will be understood as “a fast bus”.

Why does rychlý end in -ý here? Would it change with a different noun?

Rychlý is an adjective meaning fast. In Czech, adjectives must agree with the noun in:

Gender (masculine / feminine / neuter)
Number (singular / plural)
Case

Here the noun autobus is:

masculine
singular
nominative (the subject of the sentence)

So the basic masculine singular nominative ending for adjectives is -ý:

rychlý autobus = fast bus

If the noun changed, the adjective would change too:

rychlá tramvaj (feminine singular) – fast tram
rychlé auto (neuter singular) – fast car
rychlé autobusy (masculine plural) – fast buses

So the -ý ending is there because autobus is masculine singular in the nominative.

Why is it je dobrý and not je dobře?

The difference is:

dobrý – adjective = good
dobře – adverb = well

In this sentence, dobrý describes autobus (a noun), so you need an adjective, just like in English:

Autobus je dobrý. – The bus is good.
(adjective describing the bus)

You would use dobře to describe how something is done, or how something happens:

Autobus jezdí dobře. – The bus runs well.
Cítím se dobře. – I feel well.

So here je dobrý is correct, because you are saying the bus is good (for my family), not that it does something well.

Why does rodinu end in -u instead of rodina?

The basic dictionary form is rodina (family), which is feminine singular nominative.

But after the preposition pro (“for”), Czech uses the accusative case.

Nominative (dictionary/subject form): rodina
Accusative (direct object, after pro): rodinu

So:

Moje rodina je velká. – My family is big. (subject → nominative)
Mám velkou rodinu. – I have a big family. (object → accusative)
Je to dobré pro moji rodinu. – It is good for my family. (after pro → accusative)

That is why the sentence has rodinu, not rodina.

What exactly does pro mean here, and which case does it require?

Pro usually corresponds to for in English, often showing a beneficiary or intended recipient:

dárek pro tebe – a present for you
čas pro rodinu – time for (the) family

Grammatically, pro always takes the accusative case. That’s why you see:

pro moji rodinu (accusative)
not pro moje rodina (wrong case and wrong form).

So in your sentence, pro moji rodinu means for my family and is in the accusative because of pro.

Why is it pro moji rodinu and not pro moje rodina?

Two things are happening here:

Case change because of pro:
- rodina (nominative) → rodinu (accusative) after pro.
Agreement of the possessive pronoun with the noun:
- The pronoun “my” must also be in the accusative feminine singular to match rodinu.

Correct forms:

pro moji rodinu – standard, very common
pro mou rodinu – also correct, a bit more formal / bookish

Wrong in standard Czech:

pro moje rodina – wrong case on rodina and wrong form of the pronoun.

So pro moji rodinu is used because both moji and rodinu are in the accusative, and they agree in gender (feminine) and number (singular).

What’s the difference between moje, moji/mojí, and mou? Which should I use with rodinu?

All of these are forms of the possessive pronoun můj / moje (“my”), but they are used in different cases or styles.

With rodina / rodinu (feminine singular), the most relevant forms are:

moje rodina – nominative: my family (as subject)
- Moje rodina bydlí v Praze. – My family lives in Prague.
moji rodinu – accusative (very common)
- pro moji rodinu – for my family
- Vidím moji rodinu. – I see my family.
mou rodinu – also accusative, somewhat more formal / traditional
- pro mou rodinu – for my family
mojí rodiny / mojí rodině / mojí rodinou – other cases (genitive, dative, instrumental, etc.), often with a long í:
- bez mojí rodiny – without my family (genitive)
- s mojí rodinou – with my family (instrumental)

In everyday speech and writing, with pro … rodinu you will mainly hear:

pro moji rodinu (very common, neutral)
pro mou rodinu (correct, a bit more formal)

As a learner, pro moji rodinu is a safe and natural choice here.

Could I also say Autobus je rychlý a je dobrý pro moji rodinu or Autobus je pro moji rodinu dobrý? How does word order change the meaning?

All of these sentences are grammatically correct, but the emphasis changes slightly.

Rychlý autobus je dobrý pro moji rodinu.
- Focus: “The fast bus (as a type) is good for my family.”
- You’re highlighting a specific kind of bus: the fast one.
Autobus je rychlý a je dobrý pro moji rodinu.
- Literally: “The bus is fast and it is good for my family.”
- Two separate statements:
  - it is fast
  - and it is good for my family
Autobus je pro moji rodinu dobrý.
- Word order shifts emphasis slightly onto pro moji rodinu.
- Roughly: “The bus is good for my family (that’s the important part).”

Czech word order is more flexible than English, but not random. Here all versions are acceptable; you mainly choose based on what information you want to stress at that moment.

How would the adjectives change if the noun were feminine, neuter, or plural instead of autobus?

Adjectives must match the gender and number of the noun.

Original (masculine singular):

Rychlý autobus je dobrý pro moji rodinu.
- rychlý / dobrý – masculine singular

Other genders/numbers:

Feminine singular – e.g. tramvaj (tram)
- Rychlá tramvaj je dobrá pro moji rodinu.
  - rychlá tramvaj
  - je dobrá
Neuter singular – e.g. auto (car)
- Rychlé auto je dobré pro moji rodinu.
  - rychlé auto
  - je dobré
Masculine plural – e.g. autobusy (buses)
- Rychlé autobusy jsou dobré pro moji rodinu.
  - rychlé autobusy
  - jsou dobré
Feminine plural – e.g. tramvaje
- Rychlé tramvaje jsou dobré pro moji rodinu.

So you can see the pattern:

Masculine sg: -ý (rychlý, dobrý)
Feminine sg: -á (rychlá, dobrá)
Neuter sg: -é (rychlé, dobré)
All plural here: -é (rychlé, dobré)

Can I omit je in this sentence, like in some other languages that drop “is”?

In standard Czech, you do not normally omit je in the present tense.

Correct: Rychlý autobus je dobrý pro moji rodinu.
Rychlý autobus dobrý pro moji rodinu. – sounds incomplete / non‑standard.

In casual speech, people might drop je in very short phrases or headlines, but in normal sentences learners should always include the verb je (“is”):

je – he/she/it is
jsou – they are

So for correct, natural Czech, keep je in this sentence.

How do you pronounce Rychlý autobus je dobrý pro moji rodinu? Any tricky sounds I should watch out for?

Key points:

Stress
- In Czech, stress is always on the first syllable of each word:
  - RYCH‑lý AU‑to‑bus je DO‑brý pro MO‑ji RO‑di‑nu
The sound ch in rychlý
- ch is a single consonant, like the ch in German Bach or Scottish loch.
- It is not like English ch in church.
Long vowels
- ý in rychlý and dobrý is a long i‑sound (like a long ee):
  - rychlý ≈ “rikh‑lee” (with a harsh ch, not an English k)
  - dobrý ≈ “dob‑ree”
- Keep the vowel clearly longer than in rychlý vs a hypothetical short rychly.
r in Czech
- Always trilled or tapped, never the English “er”.
- Short tap, like the Spanish r in pero.
Letter j
- j is pronounced like English y in yes:
  - je ≈ “ye”
  - moji ≈ “mo‑yi”

Putting it all together slowly and clearly:

RYCH‑lý AU‑to‑bus je DO‑brý pro MO‑ji RO‑di‑nu
(each word with stress on the first syllable, long ý in rychlý and dobrý, harsh ch in rychlý).