a) the adjective (eg small, big)
b) the position of the adjective after the noun
c) adjectives with the male ending –i, female –it
d) degrees of adjectives (eg good, better, best)
e) The dual-plural (eg oznayimears)

Body parts of which there are two form a special dual and end in ayim and are of female gender.

Examples:

SingularPlural
earאוזןאוזניים
ozenoznayim
eyeעיןעניים
ayinenayim
tooth שיןשיניים
shenshinayim
legרגלרגליים
regelraglayim
SingularPlural
breastשדשדיים
m shadshadayim
lipשפהשפתיים
safahsfatayim
hipמותןמותניים
m motenmotnayim
kneeברךברכיים
berechberkayim

Also certain objects form a dual-plural, but their gender is mostly male.

bycicle אופניים
ofanayim
hotplate (stove)כיריים
kirayim
crutches קביים
kabayim
bracketsסוגריים
sograyim
scissorsמספריים
misparayim
pincersמלקחיים
melkachayim

Why the word hotplates is a dual? Probably, because in pioneer times stoves had only two hotplates. Bye the way: The dual form exists similarly also in Arabic: eg. Bahrain (spoken bachrayn) means two seas, from al bachr, the sea.

Also, there are dual forms in notions of time.

noonצהריים
tzohorayim
two hoursשעתיים
sha’atayim w
two days יומיים
yomayim
two weeks שבועיים
shvu’ayjim
two months חודשיים
chodshayim
two years שנתיים
shnatayim w