"Do you have a ruler?"
This 'も' is part of the word 'もっています' and is not a ’postpositional particle’.
'もっています' means 'have' in this sentence.
So it is necessary in this sentence.
Small hiragana is not become the first letter of a word. (Except for be new Japanese words be made by high school's girls)
'っています' is not exist as a word.
Hello! Thank you for reading.
（For people who love kanji : 読んでくれてありがとう）
I had forgotten this until I saw your kind comment.
Why not? Just because some hate, there will not be more love?
I learn Japanese because of the existence of kanji culture. Everyone has their own purpose.
Thank you, but why does DLJapanese put it on a separate word tile if it is a part of a word?
Yeah, you could say that. もっている specifically means "to have" something, whereas ある can also be used to say that "there is" something.
If any native speaker could clarify this, that would be great. I also tried using あります as well.
Even "あなたは鉛筆がありますか" isn't accepted, despite it being a common way of asking if somebody has something.