Els dos preus són iguals.

Els is the masculine plural definite article, equivalent to the. It is used because preus is a masculine plural noun.

In Catalan, it is very common to use the definite article before a numeral when you mean a specific set, so els dos preus means the two prices or both prices, not just any two prices.

Yes, but the meaning changes slightly.

• els dos preus = a specific pair of prices already known in the context
• dos preus = two prices in a more general or indefinite sense

So in this sentence, els helps make it sound like you are talking about those particular two prices.

Because preu is a masculine noun.

In Catalan:

• dos is used with masculine nouns
• dues is used with feminine nouns

So:

• dos preus
• dues cases

The singular noun is preu. Its plural is formed regularly by adding -s:

• preu → preus

The spelling may look unusual to an English speaker, but it is a normal Catalan plural pattern. The eu stays, and you simply add s.

Són is the third-person plural present form of the verb ser, meaning to be.

So:

• és = is
• són = are

It matches the plural subject els dos preus.

The accent in són shows the stressed vowel and helps distinguish it from other words spelled son.

It is just the normal written form of the verb. In other words, this is not optional: són is the correct spelling.

Catalan uses ser for things like identity, classification, and equivalence. Saying that two things are equal is treated as equivalence, so ser is the natural verb.

So:

• Els dos preus són iguals is correct.
• Using estar here would sound wrong.

This is similar to Spanish, where equality also normally uses ser.

Because iguals is plural, and it agrees with the plural subject els dos preus.

Compare:

• El preu és igual = singular
• Els preus són iguals = plural

A useful detail: igual has the same form for masculine and feminine in the singular, but the plural is iguals.

Very often, yes.

In a sentence like this, els dos preus can naturally correspond to both prices in English. Catalan often expresses this idea with the article + numeral pattern.

You may also see tots dos in other sentences, which can also express both.

No, this is the normal, neutral word order:

• subject: Els dos preus
• verb: són
• complement/adjective: iguals

This is the standard way to build a sentence with ser plus an adjective.

A rough guide is:

els doz PREWS son ee-GWALS

A few notes:

• preus is one syllable, roughly like prews
• iguals has the gw sound in the middle
• són has a clear o sound

Exact pronunciation varies a bit by dialect, but this rough version will help you get started.