The “cases” in Portuguese

There are no cases in the Portuguese language.
Unlike English where there are three cases: subjective, objective and possessive, otherwise known as nominative, accusative and genitive.
Case indicates the role of the nouns.

But how can I recognise the case of a noun?

You can tell by the sentence structure.
Portuguese sentences follow this order:
subject (nominative) – predicate – object (dative/accusative)

The use of prepositions in Portuguese and English differ.
When you become familiar with whole phrases you will understand how prepositions work in Portuguese.
Portuguese uses prepositions to mark cases.
For example, the genitive is built by using the preposition “de” (of) to mark belongings.
 
💬 e.g.
🇵🇹 a casa do [de+o] João ‒ 🇬🇧 the house of João
🇵🇹 o pai da [de+a] Amália ‒ 🇬🇧 Amália’s father

Following the preposition "a" (at, on, in, after, around, to), you will find the dative.
 
💬 e.g.
🇵🇹 Eu dou a CD a Amália. ‒ 🇬🇧 I give the CD to Amália.
🇵🇹 Podes trazer o livro para a Catherine? ‒ 🇬🇧 Could you take the book to Catherine?

➠ Adjectives in Portuguese