Příjem je v potvrzení o příjmech.

Příjem is in the nominative singular because it is the subject of the sentence.

• Příjem = income
• je = is
• v potvrzení o příjmech = in the certificate/confirmation of income

So grammatically, the structure is:

• Příjem = subject
• je = verb
• v potvrzení o příjmech = prepositional phrase

Because the preposition v meaning in usually requires the locative case.

The noun potvrzení is a neuter noun ending in -í, and for this type of noun, the nominative and locative singular often look the same.

So:

• nominative: potvrzení
• locative after v: v potvrzení

That is why the form does not change visibly here.

Because the preposition o in the sense of about/concerning takes the locative case.

The base noun is:

• příjem = income

Its plural forms include:

• nominative plural: příjmy
• locative plural: příjmech

So:

• o příjmech = about incomes / concerning income

In the phrase potvrzení o příjmech, the meaning is something like a certificate/confirmation about income/earnings.

This is a very natural question. Czech often uses different number forms depending on meaning and on fixed expressions.

• příjem at the start is singular, meaning income as a general concept or one person's income.
• potvrzení o příjmech is a common set phrase where the plural příjmech is used more like earnings/income details.

So even though English might prefer singular in both places, Czech often uses the plural in official expressions like this.

You can think of potvrzení o příjmech as a standard document name, similar to proof of earnings.

Potvrzení usually means confirmation, certificate, or written proof.

In this sentence, potvrzení o příjmech is best understood as:

• income certificate
• proof of income
• confirmation of income/earnings

The exact English translation depends on context, especially whether this is an official document for an employer, bank, office, and so on.

Yes, you could change the word order, but the emphasis would change.

The original:

• Příjem je v potvrzení o příjmech.

puts příjem first, so it sounds like the sentence is mainly about the income.

If you say:

• V potvrzení o příjmech je příjem.

the sentence starts with the location/document, so it sounds more like In the income certificate, there is income or The income is in the certificate with different focus.

Czech word order is more flexible than English, but it is not random. It often shows what is already known and what is being emphasized.

Je is the 3rd person singular present tense of být (to be).

So:

• já jsem = I am
• ty jsi = you are
• on/ona/ono je = he/she/it is

Here it matches the singular subject příjem, so:

• Příjem je... = The income is...

A rough pronunciation guide:

• příjem ≈ PZHEE-yem
• příjmech ≈ PZHEE-ye-mekh

A few important points:

• ř is the famous Czech sound with no exact English equivalent. It is somewhat like a mix of r and zh.
• í is a long ee sound.
• j is pronounced like English y.
• ch is like the ch in Scottish loch or German Bach, not like English church.

So příjem is roughly př + í + jem.

Yes, definitely. It is very useful to learn potvrzení o příjmech as one whole expression.

Many official Czech phrases work this way, and it is often easier to remember them as chunks rather than building them from scratch every time.

Useful chunk:

• potvrzení o příjmech = proof/confirmation of income

This also helps you remember that:

• o takes the locative
• the noun becomes příjmech

Yes. In this sentence, v clearly means in, but more generally it can also mean inside, at, or sometimes during, depending on context.

Examples:

• v domě = in the house
• v Praze = in Prague
• v pondělí = on Monday

So learners should not expect a one-to-one match with English. Here, though, v potvrzení is straightforwardly in the certificate/document.