The preposition "a" in Portuguese has multiple uses, but I would avoid comparing it to Spanish, as some of them may differ, which is why all your examples in the Portuguese translation are wrong, except for the third one. In the first case, for the verb "chamar", there is no need to use the preposition "a", much like you wouldn't in English, so in that case the correct form would be "Chamo as garotas" (lit: I call the girls) The same goes for the second example. The verb "ver" doesn't need the preposition either, so you'd say "Vejo o carteiro" (lit: I see the mailman) The third example is correct because you actually didn't use the preposition! For the fourth example doesn't use the preposition either and the final example would be "A menina adora o seu gatinho" (lit: The girl loves your kitty). In all of your examples, the direct complement answered the verb: 1. Who did you call? 2. Who did you see? 3. What did you have? 4. Who did you see? 5. What did she love? In Portuguese you don't need to use "a" to answer the direct complement. Instead you use it for the indirect complement, which answers the question "To whom?" Examples would be: "Eu dou o presente ao [a+o] Ricardo" "Eu liguei ao João" (I called [by phone] João) Another use of "a" in Portuguese is of dislocation, as with "para", such as "Eu vou a casa do Pedro" (I'm going to Pedro's house) "Eu vou aos Estados Unidos" (I'm going to the US) So in general, I would avoid drawing comparisons with Portuguese and Spanish in terms of prepositions, as they can frequently cause mixups, such as this one! Keep up the good work!

Hi! the verbs "chamar", "adorar" e "ver" don´t ask for preposition. They are transitive verbs in portuguese. So, the "a"/"o" that follows isn´t a pronoun but an article!!! And that´s why the article must follow the gender of the noum. Don´t study spanish with portuguese. They are different. Also the portuguese of Portugal is pretty different from Brasil. Such as...the answer of the VASCO DUARTE (who is from Portugal) is wrong for us brazilians. You can´t say "Eu liguei ao João", but "eu liguei PARA o João". The same as "Eu vou a casa do Pedro", when the correct phrase is "vou PARA a casa de Pedro". As you see...if even the portuguese of Portugal doesn´t match with the portuguese of Brasil, the Spanish shouldn´t be a comparison to study portuguese. Bye!

In time...this "a" you asked about is a preposition in many examples you gave, and not a personal pronoun!

Podemos dizer que "a" não é um pronome pessoal e sim um artigo!