La policía cierra la calle por seguridad.

In Spanish la policía refers to the police force or law‐enforcement institution as a whole. Although English uses a plural verb (“the police are…”), Spanish treats la policía as a singular, feminine noun. You only switch to plural (los policías) when you mean individual officers.

Key points:

• La policía = “the police” (the department or force)
• Feminine singular, so verbs and articles agree accordingly (e.g., la policía cierra).
• To talk about officers:
  • el policía (male officer)
  • la policía (female officer)
  • los policías (multiple officers)

• Por introduces a reason or cause: “because of security.”
• Para usually indicates purpose or goal: “in order to.”

In safety contexts, Spanish almost always uses por to express the reason behind a preventive action:
• La policía cierra la calle por seguridad. (“The police close the street for safety reasons.”)

Using para here would sound unnatural because you’re not talking about the intended outcome (“in order to have security”), but the cause or motivation.

Yes, you can expand it:

• por motivos de seguridad
• por razones de seguridad
  Both mean “for security reasons,” and they sound a bit more formal or explicit.

Spanish accent rules: words ending in a vowel, –n or –s are stressed on the penultimate syllable by default. Without an accent, policia would be pronounced po-LI-cia. The written accent on the í tells you to stress that syllable: po-li-CI-a.

Pronunciation guide:
• po (like “po” in “polite”)
• li-CI-a: stress on CI (like “see-ah”)
So it’s /po-li-ˈsi-a/.

Yes, depending on the region and nuance:

• bloquear la calle – to block the street (emphasizes obstruction)
• cortar la calle – to cut off the street (common in colloquial contexts, e.g., protests)

But cerrar la calle is the standard, neutral way to say “close the street” (e.g., for police, roadworks).

Absolutely. You can use:

• Present progressive: La policía está cerrando la calle por seguridad. (emphasizes the action is in progress)
• Present perfect: La policía ha cerrado la calle por seguridad. (the street is already closed)

Choose based on whether you want to stress “ongoing action” (está cerrando) or “completed action” (ha cerrado).