At first I thought there was no one in the room.
起初我以为房间里没人。
"Who was that on the phone?" "No one you would know."
“谁来的电话？”“你不认识的人。”
I'd like to go to the concert but no one else (= no other person) wants to.
我想去听音乐会，但其他人都不愿意去。
No one told me she was ill.
没人告诉我她病了。
