Rule 1: Iẓhār: the clear nūn
Iẓhār (إِظْهَارٌ) means "making clear". When nūn sākina or tanwīn is followed by one of the six throat letters, ء هـ ع ح غ خ, the nūn is pronounced plainly from its own point, with no lengthened nasal sound and no pause. The throat letters are too far from the nūn's point for any blending to happen, so the nūn simply stays itself. Because the six letters all come from the throat, this rule is called iẓhār ḥalqī, the throat iẓhār.
أَنْعَمْتَ
anʿamta
You bestowed favour
نْ before ع inside one word (1:7).
مِنْ خَوْفٍ
min khawfin
from fear
نْ before خ across two words (106:4).
عَنْهُ
ʿanhu
from him
نْ before هـ (111:2).
كُفُوًا أَحَدٌ
kufuwan aḥad
anyone equal
tanwīn before hamza; say kufuwan with a clear n (112:4).
وَانْحَرْ
wanḥar
and sacrifice
نْ before ح (108:2).
مَنْ أَعْطَىٰ
man aʿṭā
whoever gives
نْ before hamza (92:5).