Rule 1: 1. The noun takes its construct shape
A noun with a suffix behaves as the first term of an iḍāfa, because it is one: بَيْتُكَ is built like بَيْتُ عُمَرَ. Hence: a noun in tāʾ marbūṭa writes ت (جَدَّةٌ, جَدَّتُكَ); the dual drops its نِ (وَلَدَانِ, وَلَدَاكَ; oblique وَلَدَيْنِ, وَلَدَيْكَ); the sound masculine plural drops its نَ (مُعَلِّمُونَ, مُعَلِّمُوكَ; oblique مُعَلِّمِيكَ); and أَبٌ, أَخٌ use their long forms أَبُو, أَبِي, أَبَا.
جَدَّتُنَا فِي الْبَيْتِ.
jaddatunā fi-l-bayti
Our grandmother is at home.
ة → ت before the suffix.
وَلَدَاكَ فِي الْمَدْرَسَةِ.
waladāka fi-l-madrasati
Your two children are at school.
Dual nominative without نِ.
رَأَيْتُ مُعَلِّمِيكَ فِي السُّوقِ.
raʾaytu muʿallimīka fi-s-sūqi
I saw your teachers in the market.
Sound plural, accusative, without نَ.
ذَهَبَ أَبُوهُ مَعَ أَخِيهِ إِلَى الْمَسْجِدِ.
dhahaba abūhu maʿa akhīhi ila-l-masjidi
His father went with his brother to the mosque.
أَبُو nominative, أَخِي genitive after مَعَ.
سَأَلْتُ أَبَاكِ عَنْ زَوْجِ خَالَتِكِ.
saʾaltu abāki ʿan zawji khālatiki
I asked your (f.) father about your aunt's husband.
أَبَا accusative; خَالَةٌ → خَالَتِ.