1. As a conjunction expressing simultaneity:
* Mientras: This is the most common translation for "while" when used to indicate that two things are happening at the same time.
* Example: "Mientras tú lees, yo cocinaré la cena." (While you read, I'll cook dinner.)
2. As a conjunction expressing contrast:
* Mientras que: This translation is used when you want to contrast two things.
* Example: "Mientras que ella es alta, él es bajo." (While she is tall, he is short.)
3. As a noun meaning "a while":
* Un rato: This is the most common translation for "a while" as a noun.
* Example: "Esperaré un rato." (I'll wait a while.)
4. As an adverb meaning "for a while":
* Por un rato: This is used when you want to say something happened "for a while".
* Example: "Estuvieron hablando por un rato." (They were talking for a while.)
It's important to consider the context of the sentence to determine the best translation of "while" in Spanish.