Opravdu si myslíš, že ta prodavačka byla unavená?

In this sentence, si is part of the fixed expression myslet si, which means to think / to believe / to have the opinion that...

It often does not have a separate meaning you would translate word-for-word into English. You should learn myslet si as a unit.

Why it matters:

• myslet si, že... = to think that...
• myslet na... = to think about...
• myslet without si can sound incomplete or can mean something slightly different depending on context.

So here, myslíš si, že... is the normal way to say you think that...

Myslíš is the 2nd person singular present tense form of myslet si.

It matches you when speaking to one person informally:

• já si myslím = I think
• ty si myslíš = you think
• on/ona si myslí = he/she thinks

So Opravdu si myslíš... means you are asking one person directly.

If you were speaking formally or to more than one person, you would say:

• Opravdu si myslíte, že...?

This is because si is a clitic in Czech. Clitics usually go in the second position in the clause, not just anywhere.

In Opravdu si myslíš, že...

• the first element is Opravdu
• so si goes right after it

That is why Opravdu si myslíš... sounds natural.

If the sentence started with the verb, then you would get:

• Myslíš si, že...?

So both of these are possible:

• Opravdu si myslíš, že...?
• Myslíš si opravdu, že...?

But the first one is very natural because opravdu is being emphasized.

Because že introduces a subordinate clause, and in Czech, subordinate clauses are normally separated by a comma.

So:

• Opravdu si myslíš, že ta prodavačka byla unavená?

This is different from English, where you usually do not put a comma before that in a sentence like this.

A very useful rule:

• if you see že, když, protože, aby, etc., a comma is often needed.

Že means that and introduces the content of what someone thinks.

So the structure is:

• myslíš si = you think
• že ta prodavačka byla unavená = that the saleswoman was tired

This is one of the most common Czech patterns:

• Myslím si, že...
• Vím, že...
• Řekl, že...

Literally, ta is the feminine form of that.

Here, though, it often feels more like:

• that particular saleswoman
• or even something close to English the in conversation, when both speakers know who is meant

So ta prodavačka refers to a specific saleswoman.

Without ta, the sentence would still be grammatical:

• Opravdu si myslíš, že prodavačka byla unavená?

But that version is less natural in many contexts, because ta helps identify a particular person already known in the conversation.

Yes. Prodavačka is a feminine noun meaning saleswoman / female shop assistant.

Czech nouns usually have grammatical gender, and here it also matches real-life sex:

• prodavač = male shop assistant / salesman
• prodavačka = female shop assistant / saleswoman

The ending -ka is a common feminine ending.

Because prodavačka is feminine, other words connected to it must also be feminine.

Because they agree with ta prodavačka, which is feminine singular.

1. byla is the feminine singular past form of být
2. unavená is the feminine singular form of the adjective unavený = tired

Czech agreement is very important here.

Compare:

• ten prodavač byl unavený = the salesman was tired
• ta prodavačka byla unavená = the saleswoman was tired

So both the verb form and the adjective reflect the gender of the subject.

Because the sentence is talking about a past state.

• je unavená = is tired
• byla unavená = was tired

The main verb is present:

• myslíš si = do you think

But the thing you are thinking about happened in the past:

• že ... byla unavená = that she was tired

This is normal in Czech, just like in English:

• Do you think she was tired?

Yes, Czech word order is fairly flexible, but the emphasis changes.

This version:

• Opravdu si myslíš, že ta prodavačka byla unavená?

puts emphasis on opravdu = really

Other possible versions:

• Myslíš si opravdu, že ta prodavačka byla unavená?
• Opravdu myslíš, že ta prodavačka byla unavená?
  This is possible in speech, but myslíš si is the more standard learner-friendly pattern.

So the exact order can move a bit, but the original sentence is very natural and idiomatic.

A few helpful points:

• Czech stress is usually on the first syllable of the word.
• Long vowels are marked with accents, like í and á.

Examples:

• Opravdu → stress on O
• myslíš → stress on my
• prodavačka → stress on pro
• unavená → stress on u, even though the last á is long

A few sound notes:

• č in prodavačka sounds like ch in church
• š in myslíš sounds like sh
• ž in že sounds like the s in measure

So roughly:

• myslíš ≈ MIS-leesh
• prodavačka ≈ PRO-da-vach-ka
• unavená ≈ U-na-ve-naa

Yes, opravdu is completely normal and neutral. It means really.

Other common alternatives are:

• vážně = seriously / really
• fakt = really, but more informal

So you could also hear:

• Vážně si myslíš, že ta prodavačka byla unavená?
• Fakt si myslíš, že ta prodavačka byla unavená?

The original with opravdu is a good, standard choice for learners.

It is in the nominative, because it is the subject of the subordinate clause.

In:

• že ta prodavačka byla unavená

the subject is ta prodavačka, and the rest says something about her.

So:

• ta prodavačka = nominative subject
• byla unavená = was tired

If the noun had a different role, the case would change, but here nominative is exactly what you expect.