El lloguer és mensual.

In Catalan, it is very normal to use the definite article with nouns like lloguer.

So el lloguer means the rent, and Catalan often prefers that structure where English might use no article.

• El lloguer és mensual.
• Literally: The rent is monthly.

If the context is already clear, Catalan can sometimes leave things out, but the full sentence naturally uses el.

It is a noun here.

You can tell because:

• it comes after the article el
• it is the subject of the sentence
• the verb is és

So the structure is:

• El lloguer = the noun phrase
• és = the verb
• mensual = the description

The related verb is llogar.

Catalan uses ser here because mensual is describing a general characteristic or classification of the rent.

So:

• és mensual = it is monthly

This is not a temporary state or condition, so estar would not fit.

A simple way to think about it:

• ser = what something is
• estar = how or where something is, in many cases

Since this sentence describes the type/frequency of the rent, ser is the correct choice.

The accent is important in writing.

És is the 3rd person singular of ser:

• és = is

Without the accent, es is usually a different word, often a pronoun:

• es

So the accent helps distinguish two different words.

As a bonus, the accent also tells you about stress and vowel quality in standard spelling.

Mensual is an adjective. It describes lloguer.

So the sentence pattern is:

• noun + verb + adjective
• El lloguer és mensual.

A useful contrast:

• mensual = monthly, as an adjective
• mensualment = monthly, as an adverb

So here mensual is correct because it describes lloguer, not the way an action is done.

It actually does agree with the noun, but this adjective has the same form for masculine singular and feminine singular.

Here:

• lloguer is masculine singular
• so mensual is also singular

With a feminine singular noun, it would still often be mensual:

• La quota és mensual.

But in the plural, it changes:

• Els lloguers són mensuals.

So the main visible change is usually in the plural: mensuals.

They are related, but not identical.

• El lloguer és mensual = a complete sentence
• El lloguer mensual = a noun phrase

So:

• El lloguer és mensual.
  This states something about the rent.

• El lloguer mensual
  This means the monthly rent and usually needs more around it, for example:
  El lloguer mensual és alt.

In other words:

• és mensual = is monthly
• lloguer mensual = monthly rent

Not in this sentence.

• mensual is an adjective
• mensualment is an adverb

Because mensual describes the noun lloguer, the adjective is needed:

• El lloguer és mensual. ✅

If you use mensualment, you would normally need a verb of action, such as paying:

• El lloguer es paga mensualment.

So both words are correct, but they are used in different sentence structures.

A helpful approximation is:

• llo-GUER

A few useful points:

• the stress falls on the last syllable: -guer
• ll in traditional Catalan is a palatal sound, somewhat like the lli sound in English million
• in some dialects, it can sound closer to y
• gu before e keeps a hard g sound

So an English-friendly rough guide is something like lyo-GER or yo-GER, depending on the accent.

Yes, if the subject is already understood from context.

For example, if someone asks about the rent, you can answer:

• És mensual.

That works because el lloguer is understood.

But if you are giving the full sentence on its own, El lloguer és mensual is the clearer and more complete form.