El gat és sota la taula.

Catalan nouns have grammatical gender.

• el = masculine singular the
• la = feminine singular the

So:

• el gat = masculine noun
• la taula = feminine noun

This is similar to Spanish or French, but unlike English, where the never changes.

A few useful article forms:

• el = masculine singular
• la = feminine singular
• els = masculine plural
• les = feminine plural

You usually have to learn the noun together with its article.

Literally, gat is the masculine form, and gata is the feminine form.

• el gat = the male cat
• la gata = the female cat

In real usage, though, the masculine form can sometimes be used more generally when the sex is unknown or not important. So depending on context, el gat may mean the male cat or just the cat in a generic way.

És is the 3rd person singular of ser: he/she/it is.

A very common learner question is whether location should use ser or estar. In Catalan, this works differently from Spanish.

For a simple statement of location, ser is often perfectly normal:

• El gat és sota la taula.

In many contexts, you may also hear:

• El gat està sota la taula.

Broadly speaking:

• ser can sound like a neutral statement of where something is
• estar can emphasize the current position or state more strongly, and is also common in many varieties

So for a learner, the important point is:

• és is not a mistake here
• està may also be possible depending on dialect and nuance

The accent mark is important because it distinguishes és from es.

• és = is
• es = a pronoun, as in reflexive constructions

Examples:

• El gat és aquí. = The cat is here.
• Es renta. = He/She washes himself/herself.

The accent also helps show pronunciation and stress.

Sota is a preposition. It means under or beneath.

It does not change form:

• sota la taula = under the table
• sota el llit = under the bed
• sota les cadires = under the chairs

So unlike nouns or adjectives, sota stays the same no matter what comes after it.

In a normal sentence like this, you usually need the article.

• El gat sounds natural
• La taula sounds natural

Without the article:

• Gat és sota taula

this sounds wrong or very unnatural in ordinary Catalan.

Catalan, like the other major Romance languages, normally uses articles with specific countable nouns. Since we are talking about a particular cat and a particular table, el and la are expected.

A rough pronunciation guide is:

el gat és sota la taula
el GAHT ez SO-ta la TOW-la

A few notes:

• gat ends in a clear t
• és sounds like ez
• sota has the stress on the first syllable: SO-ta
• taula also has first-syllable stress, and au sounds a bit like ow in cow

In much of Central Catalan, unstressed vowels are reduced, so you may hear something closer to:

uhl GAHT ez SOH-tuh luh TOW-luh

If you want, I can also break the whole sentence down word by word with pronunciation and grammar labels.