Acostarse = to go to bed

If you are tired after a long day of doing whatever and you are ready to go to bed, you have to know how to say it in Spanish. Acostarse is a reflexive verb because it literally means to put one's self to bed. Por ejemplo, I could say, "Me acuesto a las diez y media de la noche." This sentence transolate to, "I go to bed a 10:30 at night."