No mercado, as cerejas estão baratas esta semana.

No is a contraction of em + o:

• em = in / at
• o = the (masculine singular article)

So:

• no mercado = in the market / at the market

Portuguese very often contracts em with the definite article:

• em + o = no
• em + a = na
• em + os = nos
• em + as = nas

So no mercado is the normal form, not em o mercado.

Portuguese uses definite articles more often than English.

• as = the for feminine plural nouns
• cerejas = cherries

So as cerejas literally means the cherries.

In English, we often say just cherries are cheap this week, but in Portuguese it is very natural to use the article: as cerejas.

This does not always mean a very specific set of cherries. It can also refer to cherries in general in that context, such as the cherries being sold at the market.

The singular noun is:

• a cereja = the cherry

It is feminine, so in the plural it becomes:

• as cerejas = the cherries

Because the noun is plural, the verb and adjective also have to match it:

• as cerejas estão baratas

So the sentence shows agreement in number and gender.

This is a very common question because Portuguese has two verbs meaning to be: ser and estar.

Here, estão is used because the sentence talks about a temporary state or condition:

• this week, the cherries are cheap
• next week, they may not be

So:

• estar barato = to be cheap right now / in this situation
• ser barato = to be cheap by nature or generally

Compare:

• As cerejas estão baratas esta semana. = They are cheap this week.
• As cerejas são baratas neste país. = Cherries are cheap in this country in general.

Baratas agrees with cerejas.

The adjective barato means cheap, and it changes form to match the noun:

• barato = masculine singular
• barata = feminine singular
• baratos = masculine plural
• baratas = feminine plural

Since cerejas is feminine plural, the adjective must also be feminine plural:

• as cerejas estão baratas

This kind of agreement is a basic and very important feature of Portuguese grammar.

In this sentence, baratas comes after estão because it is not directly attached to the noun. It is a predicate adjective.

Structure:

• as cerejas = subject
• estão = verb
• baratas = adjective describing the subject

So the pattern is:

• Subject + estar + adjective

That is why you get:

• As cerejas estão baratas.

This is different from an adjective placed directly next to the noun, such as:

• cerejas baratas = cheap cherries

Esta semana is a time expression meaning this week.

Portuguese often uses time expressions directly, without a preposition, just like English:

• esta semana = this week
• hoje = today
• amanhã = tomorrow

So:

• As cerejas estão baratas esta semana. = The cherries are cheap this week.

You could also hear other time phrases with prepositions in different contexts, but here no preposition is needed.

Putting No mercado at the beginning sets the scene first:

• No mercado, as cerejas estão baratas esta semana.

This is very natural in Portuguese and gives a slight emphasis to the location: at the market.

You could also say:

• As cerejas estão baratas esta semana no mercado.

That is grammatically possible, but the original version sounds smoother and more natural if you want to introduce the place first.

It can mean either, depending on context.

• mercado often means market
• supermercado specifically means supermarket

So in this sentence, no mercado could mean:

• at the market stalls
• in the market
• sometimes even in the supermarket, depending on the situation

If you want to be very specific, you can say:

• no supermercado = in the supermarket

In European Portuguese, estão has a nasal sound at the end.

A rough guide is:

• estão ≈ es-TOWN but with a more nasal ending, not a full English town

A few useful points:

• the final -ão is strongly nasal
• the first syllable is usually unstressed and can sound reduced in European Portuguese
• native European Portuguese pronunciation is often more compressed than Brazilian Portuguese

So if you say it too clearly like every written vowel is fully pronounced, it may sound less European Portuguese.

It is understandable, but estão baratas is better here.

Why?

Because esta semana suggests a temporary situation. Prices change, so Portuguese normally uses estar:

• As cerejas estão baratas esta semana.

If you say são baratas, it sounds more like a general quality, not a temporary price situation.

So for changing prices, availability, weather, and similar conditions, estar is usually the right choice.

Yes: barata can also mean cockroach as a noun.

So:

• barata = cheap (adjective, feminine singular)
• a barata = the cockroach

But in this sentence there is no real confusion, because baratas clearly works as an adjective agreeing with cerejas:

• as cerejas estão baratas = the cherries are cheap

Context makes the meaning obvious.