we all know it used to mean I am
for example
ⲁⲛⲟⲕ ⲡⲉ ⲡⲓⲛⲓϣϯ , ˋⲛⲑⲟϥ ⲡⲉ ⲡⲓⲕⲟⲩϫⲓ , and so on
all of those are definite (معرفه)
if you want to use the indefinite form (صيغة التنكير)
you should say something like
ˋⲛⲑⲟϥ ⲟⲩⲛⲓϣϯ ⲡⲉ
ˋⲛⲑⲟⲥ ⲟⲩⲛⲓϣϯ ⲧⲉ
ˋⲛⲑⲱⲟⲩ ϩⲁⲛⲛⲓϣϯ ⲛⲉ
but u should say
ⲁⲛⲟⲕ ⲟⲩⲛⲓϣϯ
ⲡⲉ (without ⲡⲉ)
ˋⲛⲑⲟⲕ ⲟⲩⲛⲓϣϯ
ˋⲛⲑⲟ ⲟⲩⲛⲓϣϯ
and so on
the reason is that ⲡⲉ,ⲧⲉ and ⲛⲉ means he,she and they (
reference Coptic in 20 lessons by Bentley Layton)
so you can say ˋⲛⲑⲟϥ ⲟⲩⲛⲓϣϯ ⲡⲉ (he is great he) or simply ⲟⲩⲛⲓϣϯ ⲡⲉ (he is great) without ˋⲛⲑⲟϥ
for example in the prayer (ⲁⲓⲛⲁϩϯ) it says
ⲟⲩⲛⲓϣϯ ⲡⲉ ⲡⲱⲟⲩ ˋⲛⲧⲉ ⲧⲉⲡⲉⲣⲑⲉⲛⲓⲁ
and in the second ϩⲱⲥ they say
ϫⲉ ⲟⲩⲭⲣⲓⲥⲧⲟⲥ ⲟⲩⲁⲅⲁⲑⲟⲥ ⲡⲉ
but NEVER say, ˋⲛⲑⲟⲕ ⲟⲩⲭⲣⲓⲥⲧⲟⲥ ⲡⲉ instead sometimes might say ˋⲛⲑⲟⲕ ⲟⲩⲭⲣⲓⲥⲧⲟⲥ ˋⲛⲑⲟⲕ
or ⲁⲛⲟⲕ ⲟⲩϩⲏⲕⲓ ⲁⲛⲟⲕ
In Sahidic there is no ˋⲛⲑⲟϥ ˋⲛⲑⲟⲥ nor ˋⲛⲑⲱⲟⲩ they always use ⲡⲉ,ⲧⲉ and ⲛⲉ insead
this is a little info I wanted to share with everybody and hope it helps
