Suffixes fall into three categories, +, - and ±. The first type, the plus type, is the plain agglutinative one, the suffix is just added to the stem. The second type (-) tells that the suffix can only be added to a vowel-final stem, so it removes an eventual final consonant from the stem, and the third type (±) is stem-sensitive, so that it truncates the final consonant from some stems, but not from others.
Example nouns
stem rel pl nut
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p-decl {-p} {-t} {-nut}
tuttu tuttup tuttut tuttunut
angutE angutip angutit angutinut
qimmiq qimmip qimmip qimminut
p-variety {-p} {-t} {-nut}
miir(q)aq meeqqap meeqqat meeqqanut
atuag(k)aq atuakkap atuakkat atuakkanut
kalaal(l)iq kalaallip kalaallit kalaallinut
Transitional {-up} {-it} {+nut}
kangirluk kangerluup kangerluit kangerlunnut
panik paniup paniit paninnut
up-decl {±up} {±it} {+nut}
irniq ernerup ernerit ernernut
The p-variety stems all have a short fricative in the stem (v, s, l, j, g, r), this one is lengthened in front of a consonantal minus suffix.
The p-variety stems are gradually shifted to both the p-declension and the up-declension(?). For taliq + mi we have 3 different forms: tallimi (tal(l)iq+mi) (correct), talimi (taliq+mi (regularized), talermi (taliq+mi) ("wrong", but very often)
All the suffixes of the p-declension are minus-suffixes (they remove a final consonant)
The suffixes of the up-declension are plus/minus-suffixes