I can speak Spanish and French, and I am currently learning Portuguese. During my learning, I realized that there are some unique features in Portuguese — I don't speak Italian, so I don't know if those are also present in Italian. In particular, I found the following quite amusing:
The fact that you can use definite article in front a person's name or possessive pronoun (this is the opposite of what we have been taught in English, French and Spanish, and I was surprised when I first learnt it): a minha roupa (my clothes), O João ("the" João)
Contraction of articles is extensive in Portuguese. Spanish only has a + el ⟶ al and de + el ⟶ del, and French have some, for example, de + le ⟶ du and a + le ⟶ au. But, in my impression, all propositions in Portuguese are contracted with definite pronoun (o, a), demonstrative pronoun (essa, esse,...), indefinite pronouns (um, uma)
Are there specific terminologies for the above-mentioned phenomena in Portuguese? And why has Portuguese absorbed and combined so many features from Spanish and French? As someone who can speak both languages, it did make it easier to understand some grammatical rules in Portuguese.