①I will never forget the day when I joined the army.
②We have no idea when she was born.
在①句中,加粗部分是定语从句,when在从句中作状语,它可以转换成on which的形式;
在②句中,加粗部分是同位语从句, when在从句中充当状语,但不能转换成"介词+关系代词"的形式。
③This is the house where I lived two years ago.
④He put forward to the question where the meeting would be held.
在③句中,加粗部分是定语从句,where在从句中作状语,它可以转换成in which的形式;
在④句中,加粗部分是同位语从句, where在从句中充当状语,但不能转换成"介词+关系代词"的形式。
⑤This is the reason why she will not attend the meeting.
⑥The teacher had no idea why Jack was absent.
在⑤句中,加粗部分是定语从句,why在从句中作状语,它可以转换成for which的形式;
在⑥句 中,加粗部分是同位语从句,why在从句中充当状语,但不能转换成"介词+关系代词"的形式。