Learn Portuguese (Portugal): O arrendamento é caro.

É comes from the verb ser, which we use for permanent or defining characteristics. Describing the lease as an expensive one is treated as a core characteristic of this specific tenancy, rather than a temporary state.

Is arrendamento the money you pay for rent?

Not exactly. O arrendamento refers to the tenancy, the lease agreement, or the act of renting. If you want to talk about the actual monthly rent payment, you would usually use the word a renda.

Why does caro end in -o?

Adjectives in Portuguese have to match the gender of the noun they describe. Since arrendamento is a masculine noun (as shown by the masculine article o), the adjective must also take the masculine form, caro. If we were describing a feminine word like a casa (the house), it would be cara.

Is there a trick to remembering the gender of arrendamento?

Yes! Nouns ending in the suffix -mento in Portuguese are almost always masculine. This is a handy pattern to remember for choosing the correct articles (like o) and adjective endings.