Spanish phrase
Siento mucho ~.
Meaning
I am deeply sorry for ___.
When to use it
A very polite expression of deep regret. Suitable for apologies to professors, officials, or in formal letters, showing sincere remorse.
Example dialogue
Entiendo, pero debes entregar la tarea pronto.
I understand, but you must submit the assignment soon.
Siento mucho no haber entregado la tarea a tiempo.
I am deeply sorry for not submitting the assignment on time.