● Study the complete forms of the prepositions لـ and بـ with attached pronouns:
Person and genderSingularDualPlural
Third-person masculineلَهُ / بِهِلَهُمَا / بِهِمَالَهُمْ / بِهِمْ
Third-person feminineلَهَا / بِهَالَهُمَا / بِهِمَالَهُنَّ / بِهِنَّ
Second-person masculineلَكَ / بِكَلَكُمَا / بِكُمَالَكُمْ / بِكُمْ
Second-person feminineلَكِ / بِكِلَكُمَا / بِكُمَالَكُنَّ / بِكُنَّ
First personلِي / بِيلَنَا / بِنَالَنَا / بِنَا
● Important rule: When the preposition لـ joins pronouns, it takes a fatḥah as لَـ, except with the first-person singular, where it remains لِي.