Learn Hardcore Portuguese (Brazil): A rua principal está em obras, então precisamos encontrar outra. - The main street is under construction, so we need to find another one.

em obras (literally “in works”) is the most idiomatic way to say “under construction” in Brazilian Portuguese when referring to streets, buildings, bridges, etc.
em construção focuses strictly on the act of building something from scratch (e.g. “a casa está em construção”).
Here, because we’re talking about roadworks/repairs on a street, em obras sounds more natural.

Why is obras plural in em obras?

In Portuguese, obras refers collectively to all the individual tasks, teams and equipment involved in the construction or repair process. Even if it’s just one project, we still use the plural obras to emphasize it’s a set of works, not a single “construction.”

What does então mean here, and can I use por isso instead?

então = “so” or “therefore,” used to connect cause and effect informally.
por isso = “because of that,” slightly more formal or emphatic.
You can say both: • …está em obras, então precisamos…
• …está em obras, por isso precisamos…
They’re interchangeable, but então is more common in spoken Brazilian Portuguese.

Why do we say a rua principal with the article a? In English we just say “main street.”

Portuguese almost always uses definite articles before nouns:

a rua = “the street.”
In English, you can omit “the” in names (“Main Street”), but in Portuguese you keep a:
a Rua Principal would be the official name, but even generically we say a rua principal.

Why is there no preposition after precisamos before the verb encontrar?

Portuguese grammar:

precisar de + noun (e.g. precisamos de ajuda).
precisar + infinitive verb (no de) when you mean “need to do something”: • precisamos encontrar = “we need to find.”
Adding de before an infinitive (precisamos de encontrar) is incorrect.

Why is outra standing alone? Shouldn’t it be outra rua?

outra is a pronominal adjective substituting the noun it refers to (here, rua). Because rua was already mentioned, you omit it to avoid repetition:

não podemos usar essa rua, vamos encontrar outra = “we can’t use that street, let’s find another (street).”

How do we know outra is feminine singular?

It agrees with the noun it replaces:

rua is feminine singular, so you use outra.
For a masculine noun (e.g. caminho), you’d say precisamos encontrar outro.

Could we use procurar instead of encontrar here?

Yes, but with a nuance difference:

procurar = “to look for” (the search process).
encontrar = “to find” (the successful outcome).
If you want to stress the act of searching:
• precisamos procurar outra
If you focus on discovering/finalizing:
• precisamos encontrar outra (as in “let’s pinpoint one”).

Can I say a rua principal está em reforma instead of em obras?

Yes, reforma means renovation or overhaul:

em reforma = undergoing a renovation project, often interior or specific upgrades.
em obras is broader, covering any repairs or construction work.
Both are correct, but em obras is more general for roadworks.

Why is principal placed after rua? In English adjectives usually come before nouns.

Portuguese generally places descriptive adjectives after the noun:

rua principal, casa grande, problema difícil.
Some adjectives can come before the noun for emphasis or poetic effect, but the default order is noun + adjective.