Especially for us Brits who would call them trousers! I was wracking my brain thinking of types of underwear that end in I, and then eventually remembered JP is an American site so uses that term for trousers instead!
All modern grammar experts agree that Latin grammar rules have no place in English and that prepositions are fine at the end of sentences, particularly in informal contexts.
I totally misinterpreted the sultan question... I read it as what do you call a country ruled by a sultan (like king-> kingdom). Not name a country that is ruled by a sultan
which a type of pants are namedfor which a type of pants are namedI don't have a problem with the structure as it is, but I do think that "are" needs to be changed to "is" - it's a singular type of pants after all.