Learn Hardcore Portuguese (Brazil): Este carro velho é lento.

When you use a demonstrative adjective (este, esse, aquele) it replaces the definite or indefinite article. You do not say o este carro or um este carro—este already determines the noun.

Why are both velho and lento used, and do they have to agree with carro?

They’re both adjectives describing different qualities:

velho = age/condition
lento = speed/performance
Adjectives in Portuguese must agree in gender and number with the noun. Here carro is masculine singular, so you use velho (masc. sing.) and lento (masc. sing.).

Why does velho come after carro, instead of before, like in English?

In neutral Portuguese sentences, descriptive adjectives generally follow the noun (carro velho). Placing an adjective before the noun (e.g. velho carro) is grammatically correct but adds emphasis, a poetic tone, or a subjective nuance.

Why is é used here instead of está?

É is the 3rd person singular of ser, used for inherent or defining characteristics. Estar (as está) indicates temporary states. Since being old and slow are seen as inherent traits of the car, you use é. If you said este carro está lento, it would imply it’s slow at the moment (perhaps due to a problem).

Why does é have an accent mark and what happens if it's missing?

The acute accent on é distinguishes it from e (the conjunction “and”).

é (with accent) = 3rd person singular of ser (“is”)
e (no accent) = “and”

Without the accent, the word would be pronounced differently and change its meaning.

What is the difference between lento and devagar?

Lento is an adjective meaning slow (it describes nouns: carro lento).
Devagar is an adverb meaning slowly (it describes verbs: dirija devagar).

To say “the car is slow,” you use lento.

How would you say “These old cars are slow” in Portuguese?

You make each element agree in number:

este → estes
carro → carros
velho → velhos
é → são
lento → lentos

Result: Estes carros velhos são lentos.

What's the difference between velho and antigo when describing something as old?

velho focuses on age or condition, often implying wear or that something is outdated.
antigo emphasizes something from a past era (vintage, historic, classic).

A carro antigo is a classic/vintage car, while a carro velho is simply aged or worn.

Can I say este velho carro é lento instead of este carro velho é lento?

Yes, both are grammatically correct. Neutral Brazilian Portuguese usually places adjectives after the noun, but putting velho before the noun (velho carro) shifts the emphasis onto its age, giving a more subjective or poetic feel.