Rule 1: 1. غَيْرُ + genitive: 'other than', 'others'
With a noun or pronoun suffix in the genitive, غَيْر designates one or more things other than the one named: وَغَيْرُهُ and others (than him), غَيْرِي someone other than me. A following مِنْ names the class: وَغَيْرُهَا مِنَ الْهَدَايَا and other gifts.
جَاءَ الْعَرِيسُ وَأَبُوهُ وَغَيْرُهُمَا مِنَ الْأَقَارِبِ.
jāʾa l-ʿarīsu wa-abūhu wa-ghayruhumā mina l-aqāribi
The groom, his father and other relatives came.
غَيْرُ nominative, like the subjects it is joined to.
أَكَلَ الْحَلْوَى غَيْرِي.
akala l-ḥalwā ghayrī
Someone other than me ate the sweets.
أَرْسَلُوا ذَهَبًا وَعُطُورًا وَغَيْرَهَا مِنَ الْهَدَايَا.
arsalū dhahaban wa-ʿuṭūran wa-ghayrahā mina l-hadāyā
They sent gold, perfumes and other gifts.
غَيْرَ accusative as a further object.
تَخْتَلِفُ الْعَادَاتُ مِنْ مَدِينَةٍ إِلَى غَيْرِهَا.
takhtalifu l-ʿādātu min madīnatin ilā ghayrihā
Customs differ from one city to another.
غَيْرِ genitive after إِلَى.