This is getting pretty confusing.
Last exercise, soneone said that in Brazillian Portuguese when a verb comes before an infinitive, "de" must be left out in the sentence.
For example, duolingo marked me wrong when I to translated "but I need to return" as "mas eu preciso de voltar" arguing that "mas eu preciso voltar" is correct instead since when a verb preceeds an infinitive, "de" is left out.
So if "mas eu preciso de voltar" is wrong because of the presence of "de" in the sentence, why is "minha irma gosta de falar" correct since these sentences share almost similar conditions?
Fala can mean a speech, but that is NOT the meaning here, here you see a nominative form of the verb, you are talking about the act of speaking, not some speak. I suggest you read about the nominative forms of the verb, they are infinitive, gerund and participle, due to being nominative they do not get conjugated, but note that participle form can be either masculine or feminine, and that has nothing to do with conjugation, Portuguese verbs outside of nominative form have no gender