關系副詞用於引出定語從句，主要有when，where，why。它們後面的句子主幹完整，只缺狀語，它們都可以等於介詞+which；也就是說關系副詞和關系代詞可以相互轉化，二者的選擇主要看該關係詞在從句要充當的句法成分。

關系副詞(when、where、why)引導的定語從句,它們後面的句子主幹完整，只缺狀語，它們都可以等於介詞+ which。也就是說關系副詞和關系代詞可以相互轉化，二者的選擇主要看該關係詞在從句要充當的句法成分。

1、When

指時間,在定語從句中作時間狀語。其先行詞是表時間的名詞(如:time, day, week, month, etc.)。但並非先行詞為"時間名詞",就用when引導。當關系詞充當定語從句的狀語時,用when;當關系詞充當主語或者賓語時用which或that 引導。

I still remember the day when my brother joined the army.(作狀語，when可以轉化為on which)

I still remember the days which/that we spent together. (作spent的賓語)

2、Where

指地點在定語從句中作地點狀語。其先行詞是表示地點的名詞(如:place, school, room, etc.)。同理，先行詞是"地點名詞"時,定語從句可用where引導,還可用which/that引導，取決於該引導詞在從句中的成分。

This is the factory where he worked last year. (作狀語, where可以轉化為in which)

This is the park which/that they visited last year. (作visited的賓語)

3、Why

指原因在定語從句中作原因狀語, 先行詞通常為reason。同理，先行詞為表原因的名詞時,還要根據引導詞在從句中成分決定用why還是which/that。

The reason why he didn't come to school was that he was ill(作狀語).

I don't believe the reason (that/which) he gave me. (作give的賓語)

He asked me the reason that can explain my success. (作explain的主語)

擴展資料

關系副詞when,where和why可以用介詞+which的形式替換。

1、when=介詞+which

I will never forget the day_____ we met for the first time.

解析：先行詞是the day，後面的從句恢復到完整句為：we met for the first time on the day.因此，on the day作狀語用關系副詞when代替，如果用介詞+which，就改成on which。答案為when或on which。

2、where =介詞+which

This is the farm______ we worked when we were young.

解析：先行詞是the farm，後面的從句恢復到完整句為：we worked on the farm when we were young. 因此，on the farm可以用關系副詞where代替，如果用介詞，就改成on which。

3、why= for which

I don't know the reason ______he did it.

解析：先行詞是the reason，後面的從句恢復到完整句為：he did it for the reason. 因此，for the reason可以用關系副詞why代替，如果用介詞，就改成for which。

關系副詞一般有when、where，詳解如下。

關系副詞，兼有副詞與連接詞兩種作用，在不及物動詞的連接中要求用關系副詞。所引導的形容詞子句用於修飾主要子句中的某一名詞或代名詞，被脩飾的詞稱作先行詞，關系副詞要放在先行詞之後。例如：關系副詞when在定語從句中用作狀語，表示時間，用以脩飾表示時間的先行詞。