Both verbs “acordarse” and “recordar” mean to recall, to remember. The difference between the two of them is very small, and it is easy to get confused.
“Recordar” is a transitive verb – recordar algo = to remember something. It always requires a direct object.
Es. Recuerdo aquel día. Recuerdo que eras simpático. (= I remember that day. I remember you were nice.)
In standard Spanish, avoid using “recordar” as an intransitive verb (*recordar de) or in the pronominal form (*recordarse).
“Acordarse de” is an intransitive pronominal verb and, unlike “recordar”, is followed by the proposition “de”.
Es. Me acuerdo de tí. Se acordó de que tenía que salir. (= I remember you. He remembered that he had to leave.)
