Hello and Welcome to the forum
After all, what's
مسطف? do you mean
معطف = Coat? then we can discuss your question.
And as
klowj said, the dual is used for 2, we use plural only when its 3 and more. The verb change depending on who you are talking about (yourself (I), or him (he) or her(she) or both (dual), or many(they)...)
great work
klowj !!
