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"No sé" is a phrase which is often translated as "I don't know", and "lo siento" is a phrase which is often translated as "I'm sorry". Learn more about the difference between "no sé" and "lo siento" below.
no sé()
A phrase is a group of words commonly used together (e.g., once upon a time).
1. (general)
lo siento()
A phrase is a group of words commonly used together (e.g., once upon a time).
a. I'm sorry
Me enteré del fallecimiento de tu padre. Lo siento.I heard about the death of your father. I'm sorry.