Is someone in that room这句话的语法对吗

对，比较口语化
更简单的Somebody in that room？
更有甚者Somebody in there？（很不合语法规则，但老外都在用）
正统的说法是
Is there anyone in that room?

someone - anyone

不对
Is there someone in that room

is there anyone in that room

基本对的,但someone 该改成anyone。