Ich helfe meinem Bruder.
English: I help my brother.
Some German verbs always use the dative case for their object. This means the person or thing affected by the action is in the dative, not the accusative.
Use the dative case after certain verbs, like 'helfen', 'danken', 'gratulieren', 'gefallen', and 'gehören'. These verbs always take a dative object, not an accusative one.
Ich helfe meinem Bruder.
English: I help my brother.
Sie dankt dem Lehrer.
English: She thanks the teacher.
Wir gratulieren der Frau.
English: We congratulate the woman.
Das Buch gehört mir.
English: The book belongs to me.
Der Film gefällt dem Kind.
English: The child likes the movie.