El venedor entén el perill.

Because el is the masculine singular definite article in Catalan, meaning the.

• el venedor = the salesman / the seller
• el perill = the danger

Catalan, like English, uses the definite article before many singular countable nouns. Here both nouns are masculine singular, so both take el.

Yes. venedor is a masculine singular noun.

The feminine form is usually:

• la venedora = the saleswoman / the female seller

So:

• El venedor entén el perill.
• La venedora entén el perill.

Notice both the noun and the article change:

• el → masculine singular
• la → feminine singular

Entén is the third-person singular present form of the verb entendre, meaning to understand.

So:

• jo entenc = I understand
• tu entens = you understand
• ell/ella entén = he/she understands

The accent mark in entén shows the stressed vowel and helps distinguish pronunciation. In Catalan, accent marks are an important part of spelling and often tell you where the stress falls.

A simple learner-friendly approximation is:

• en-TEN

The stress is on the last syllable because of the accent: -tén.

More broadly:

• en sounds roughly like en
• tén sounds like TEN with stress

So the whole word is approximately en-TEN.

Yes, in this sentence the basic word order is the same:

• El venedor = subject
• entén = verb
• el perill = object

So it follows Subject + Verb + Object, just like The salesman understands the danger.

Catalan can sometimes move things around for emphasis, but this is the most neutral and common order.

Here el perill means the danger, referring to a specific danger or to danger as something identifiable in context.

Without the article, perill can appear in some expressions, but in a normal sentence like this, el perill is the natural form if you mean the danger.

So:

• entén el perill = understands the danger

This is very similar to English in this case.

The dictionary form is venedor itself, because it is a noun. It comes from the verb vendre, meaning to sell.

So:

• vendre = to sell
• venedor = seller / salesman
• venedora = saleswoman

This pattern is common in Catalan: a noun for a person can be formed from a verb.

A simple approximation is:

• puh-REEL or peh-REEL

The stress is on the second syllable: -rill.

The ll in Catalan is often pronounced somewhat like a soft ly sound, though pronunciation can vary by dialect. For an English speaker, aiming for something close to pe-REEL is a reasonable start.

Catalan also has comprendre, which can also mean to understand.

In many everyday contexts:

• entendre = to understand
• comprendre = to understand

But entendre is extremely common in ordinary speech. In a sentence like this, El venedor entén el perill, it sounds completely natural.

Depending on context, entendre can also have the sense of to hear or to grasp what someone says, much like related verbs in other Romance languages.

You would put no before the verb:

• El venedor no entén el perill.

That is the normal way to make a sentence negative in Catalan:

• subject + no + verb + object

So:

• El venedor entén el perill. = The salesman understands the danger.
• El venedor no entén el perill. = The salesman does not understand the danger.

A simple way is to use rising intonation in speech or question marks in writing:

• El venedor entén el perill?

This means:

• Does the salesman understand the danger?

Catalan often forms yes/no questions without changing the word order, especially in everyday language. Intonation does a lot of the work.