The boy who is reading needs the pen which you bought yeasterday.翻译的规律是什么 和成分顺序有关吗

yeasterday
注意拼写!
找到主干成分,The boy needs the pen.
the boy (who is reading)
the pen (which you bought yesterday)

who和which应到的定语从句修饰前面的名词
（正在读书的）男孩需要（你昨天买的）钢笔。。

那个正在读书的男孩需要你昨天买的那支钢笔。
O(∩_∩)O~

yes

找到句子的主干,主语：the boy;谓语：needs;宾语：the pen
然后看修饰成分,修饰the boy 的是定语从句who is reading(正在读书)
修饰the pen 的也是一个定语从句which you bought yesterday（你昨天买的,注意拼写）
连起来就是正在读书的那个男孩需要你昨天买的那只钢笔.
如果一眼看不出来主干,就先把谓语动词挑出来,这个比较容易,然后再去找主语和宾语

The boy (who is reading) needs the pen (which you bought yeasterday).
（正在读书的）那个男孩需要（你昨天买的）钢笔。。