This is the 7040th most frequent Spanish word.
entiendo
"I understand."
Used to indicate comprehension of someone's speech or point.
Entiendo lo que estás diciendo.
I understand what you are saying.
Used to express not comprehending or being confused about a situation.
No entiendo por qué tomaste esa decisión.
I don't understand why you made that decision.
Used to show an ongoing effort to comprehend something.