题目内容：

一道英语同义句转换
He wants to know if there is someone who can give extra music lessons.
He_______if there is someone_______extre music lessons.
前面一空中的want to know = wonder这个我知道,可后面如何把who can 转化为一个词啊,应该填什么啊~~ 谢了~~速度~~