I wish you understood that I love you. - I understand that. That's not the reason that I don't want to marry you.Ojalá entendieras que te amo. - Lo entiendo. Esa no es la razón por la cual no me quiero casar contigo.
I understand that you don't like to do your homework, but you have to do it anyway.Entiendo que no te gusta hacer la tarea, pero la tienes que hacer de todos modos.