Eastern and Western Kurdish's archaism!
Eastern Kurdish (Hawrami) and Western Kurdish (Kirdki) are so incredibly archaic among New Western Iranic languages that they actually are more archaic than Middle Persian and Parthian WHEN it comes to the grammatical cases, genders and numbers.
Of course as languages of the Middle Iranic stage, both, MP and Parthian had so many lexemes, sound structures and grammatical features that are generally lost in New Iranic. Including EK and WK.
But the archaic subdialects of EK and WK have even to this day these certain features that MP and Parthian didn't have from the earliest time of their attestation on from a point after 2'000 years ago.
Since I am more familiar with EK than with WK I will focus on EK.
EK has three cases (subject, object, vocative), two numbers (singular, plural) and two genders (masculine, feminine). MP and Parthian had two cases, which only showed in a limited way, and no grammatical gender. For example, NK also has two genders and three cases but it does not mark the gender or number of the subject case while EWK does and NK's masculine vocative marker (-o) is an innovation. In EK everything is marked even the adjectives!!! Which is an O.G. Indo-European feature that still existed in Old Iranic (Awistan and Old Persian with seven cases (nominative, accusative, dative, genitive, locative, ablative/instrumental, vocative), three genders (masculine, feminine, neuter) and three numbers (singular, dual, plural)). Latin e.g. worked like that too and Russian e.g. still does. SCNK like New Persian does not do any of this.
English
EK
SK
CK
NK
MP
-----
(A) girl sees (a) boy
(A) boy sees (a) girl
Girls see boys
Boys see girls
.
Kināca kurrī wīno
Kurr kināce wīno
Kināce kurrān wīnān
Kurre kinācān wīnān
.
Düat kurr(a) dünet
Kurr düat(a) dünet
Düat kurr dünin
Kurr düat dünin
.
Kanīshk kurr dabīnet
Kurr kanīshk dabīnet
Kanīshkān kurrān dabīnin
Kurrān kanīshkān dabīnin
.
Kac kurī dibīna
Kur kace dibīna
Kac kurān dibīnin
Kur kacān dibīnin
.
Kanīzag pisar wīnad
Pis kanīzag wīnad
Kanīzag pisarān wīnand
Pisar kanīzagān wīnand
She is healthy
He is healthy
They (only female) are healthy
They (only male) are healthy
.
Āda washa (a)na
Ād wash an
Āde washe (a)ne
Āde washe (a)ne
.
Aw xwash a
Aw xwash a
Awān xwash in
Awān xwash in
.
Aw xosh a
Aw xosh a
Awān xosh in
Awān xosh in
.
Aw xwash a
Aw xwash a
Aw xwash in
Aw xwash in
.
Oy xwash ast
Oy xwash ast
Oy xwash and
Oy xwash and
-----
He sees her
She sees him
They see them
They see her
.
Ād āde wīno
Āda ādī wīno
Āda ādīshān wīno
Āde āde wīnān
.
Aw aw dünet
Aw aw dünet
Aw awān dünet
Awān aw dünin
.
Aw aw(ī) dabīnet
Aw aw(e) dabīnet
Aw awān dabīnet
Awān aw(e) dabīnin
.
Aw we dibīna
Aw wī dibīna
Aw wān dibīna
Aw wān dibīnin
.
Oy oy wīnad
Oy oy wīnad
Oy aweshān wīnand
Oy oy wīnand
----
Note: <oy> in Middle Persian is transcribed as such but might as well be <awe>