I explain you one important thing about it. Acabar is a verb, so, you can conjugate it in present, past or future, so, if you said "Acabo de leer", it is in present, "Acabé de leer" it is in the past, "Acabaré de leer" it is in the future. In the case that you put, is correct use past or present form :D. Now, comment in spanish is comentario.