There are a few ways to say you discovered or perhaps just realized something in Portuguese. One, is actually to use the verb descobrir (to discover) but there are also three phrases that combine two verbs each, which express a similar meaning. Another, perhaps more accurate, way to look at this lesson is by keeping the phrase ‘to come to one’s knowledge’ in mind, although all three examples below are used to convey the same thing.
Tomar Conhecimento (de) – lit. to take knowledge of…
Ex. Ele tomou conhecimento do que tinha acontecido só depois de uma hora.
Ex. He found out what had happened only an hour afterwards.
Ficar Sabendo (de/que) – lit. to remain knowing about…
Ex. Eu fiquei sabendo que você não presta.
Ex. I found out that you are useless.
Vir a Saber – lit. to come to know
Ex. Vim a saber que me ligou ontem.
Ex. I came to know that you called me yesterday.
Keep in mind you may also see ‘chegar a saber‘ (to arrive to know) which can mean to find out about something but it can also be used to convey a sense of something you used to know, or knew at one moment in time (ex. Eu já cheguei a saber, mas entretanto me esqueci)