I`m the person_____wrote to you.横线上应该填who还是x

I`m the person_____wrote to you.横线上应该填who还是x
I`m the person_____wrote to you.横线上应该填who还是x

I`m the person_____wrote to you.横线上应该填who还是x
who
the person是这个定语从句的主语,放到从句中就是：the person wrote to you,用关系词who(指代人）代掉就构成了定语从句了
只有关系词在定语从句中不充当任何句子成分时可以省略,这里当主语,这么重要,一定要用who的

who.