Sprzedawca przecenił wyblakłą porcelanę.

Because sprzedawca is a masculine noun that happens to take the -a ending in the nominative singular. Polish has a group of masculine personal nouns like this, especially for professions or roles, for example:

• kierowca = driver
• mężczyzna = man
• kolega = male friend / colleague
• sprzedawca = seller / shop assistant / salesperson

So even though it looks a bit like a feminine noun at first, it is grammatically masculine when referring to a man.

Sprzedawca is a general word for someone who sells things. Depending on context, it can be translated as:

• seller
• salesman
• salesperson
• shop assistant
• sometimes vendor

In this sentence, any of those could work depending on the situation. If the sentence is about a store, shop assistant or salesperson may sound natural. If it is more general, seller works well.

Przecenił is the past tense of przecenić, and here it means marked down, discounted, or reduced the price of something.

So this is not about merely estimating value in this sentence. The verb przecenić can have different meanings in different contexts, but with an object like goods in a shop, it usually means to lower the price.

Przecenił is:

• past tense
• masculine singular
• from the verb przecenić

The ending -ł shows past tense masculine singular. Since sprzedawca is masculine singular, the verb matches it:

• sprzedawca przecenił = the seller marked down

If the subject were feminine, it would be przeceniła.
If it were plural masculine personal, it would be przecenili.

Because they are in the accusative singular, not the dictionary form.

The dictionary forms are:

• wyblakła porcelana = faded porcelain

But in this sentence, porcelain is the direct object of the verb przecenił, so it must go into the accusative case:

• porcelana → porcelanę
• wyblakła → wyblakłą

So:

• wyblakła porcelana = faded porcelain
• przecenił wyblakłą porcelanę = marked down the faded porcelain

It is in the accusative singular because it is the direct object of the verb.

The seller did something to the porcelain, so Polish uses the accusative:

• Kto? Co? in the nominative: wyblakła porcelana
• Kogo? Co? in the accusative: wyblakłą porcelanę

The adjective must agree with the noun in:

• gender
• number
• case

That is why both words change.

The basic form is wyblakły if you look it up as an adjective in the dictionary.

Its forms include:

• wyblakły = masculine singular nominative
• wyblakła = feminine singular nominative
• wyblakłą = feminine singular accusative/instrumental form

Because porcelana is feminine, the adjective must use a feminine form. And because the noun is the direct object here, it becomes wyblakłą.

Usually, yes. Wyblakły means something like:

• faded
• bleached
• washed-out

It is often used for things whose color has lost intensity, for example:

• wyblakła koszula = a faded shirt
• wyblakłe zdjęcie = a faded photo
• wyblakła porcelana = faded porcelain

So it suggests that the porcelain’s appearance has become dull or less vivid.

In Polish, adjectives usually come before the noun, just as in English:

• wyblakła porcelana = faded porcelain

That is the normal order. You may sometimes see different word order in Polish for emphasis or style, but adjective + noun is the standard pattern.

Yes. Polish word order is more flexible than English because case endings show the grammatical roles.

The neutral sentence is:

• Sprzedawca przecenił wyblakłą porcelanę.

But you could also say:

• Wyblakłą porcelanę przecenił sprzedawca.
• Przecenił sprzedawca wyblakłą porcelanę.

These versions may sound more marked or emphasize a different part of the sentence. The basic meaning stays the same because the endings still show who did what to what.

Yes, przecenić is perfective.

That means the sentence presents the action as completed:

• the seller did mark down the porcelain
• the price reduction was carried out as a finished event

The imperfective partner is often przeceniać, which would be used for repeated, ongoing, or habitual actions, depending on context.

So przecenił suggests a completed act of discounting.

A rough English-friendly guide would be:

• Sprzedawca ≈ shpshe-DAV-tsa
• przecenił ≈ pshe-TSEH-neew
• wyblakłą ≈ vih-BLAK-won
• porcelanę ≈ por-tseh-LAH-neh

A few useful pronunciation notes:

• rz is usually pronounced like the zh sound in measure, but after p in prze- it is often devoiced and sounds closer to sh
• cz sounds like ch in chop
• ł sounds like English w
• ę at the end of a word is often pronounced approximately as e or with a nasal quality depending on context

In some contexts, przecenić can relate to valuation, but in a retail sentence with sprzedawca and an item like porcelana, the most natural meaning is marked down or discounted.

So a learner should understand this sentence as a pricing action in a sales context, not as a mistaken evaluation of artistic or financial worth.

The dictionary-form phrase would be:

• wyblakła porcelana

That is the nominative singular form.
In the sentence it changes to:

• wyblakłą porcelanę

because it becomes the direct object in the accusative.

This is a very common Polish pattern: if you learn a noun together with an adjective, it helps to know both the basic form and how the phrase changes in common cases.