Questions & Answers about Lo siento, ahora mismo estoy ocupado.
Literally, lo siento means I feel it:
- lo = it
- siento = I feel / I am sorry (from sentir)
In practice, Spanish uses lo siento as a standard way to say I’m sorry. You do not need to translate it word for word when learning the phrase.
Because siento comes from the verb sentir (to feel), not ser (to be).
- sentir → siento = I feel
- ser → soy = I am
So lo siento is an idiomatic expression based on feeling, not on being.