What's the mistake?
Son las once y media por la manana, yo voy la cafateria para el almuerzo There should be a mistake with "Son las"
5 Answers
The problem is that I think you want the sentence to say "At 11:30" not "It is 11:30".
There is a also mistake with the phrase "voy la cafateria".
It is missing the word Spanish word for "to" and "cafateria" is spelled wrong.
Por is with no specific time IE por la mañana - in the morning. De is with a specific time so DE is the one to go with here. Also IR, voy etc... needs a after. I think there are about 17 verbs that need a after them, and IR is one of them. Gracias and thanks.
Son las once y media de la mañana [tilde on ñ] y voy [omit "yo"] a la cafetería.
Or as Luciente says, A las once y media de la mañana, voy a la cafetería.
Look at this link from the Reference section.
To talk about time in the past, you use the imperfect tense: "era las once..."
You could say it the way Luciente suggested, or you could say
Son las once y media por de la manana, y voy...