1. Tom’s father died on May 1st, but the day before then he had looked pretty well.

Tom’s father died on May 1st, the day before when he had looked pretty well.

2. My uncle works on a farm, and in front of it there is a lake .

My uncle works on a farm, in front of which there is a lake .

并列句讀著都非常順嘴。

第一句 the day before then 作時(shí)間狀語(yǔ)。5月一的前一天。

第二句 in front of it 作地址狀語(yǔ)。農(nóng)場(chǎng)的前面。

為何一個(gè)用關(guān)系代詞一個(gè)用關(guān)系副詞呢？

為何不是 the day before which 或 in front of where 呢？

因 為before 后能接副詞 then，而 in front of 后不可以接副詞？

1 Tom’s father died on May 1st, but the day before then he had looked pretty well.

此句中的then不是指May 1st, 而是指that time，即the time Toms father died. 即時(shí)間副詞then指代的是前一個(gè)分句謂語(yǔ)動(dòng)作發(fā)生的時(shí)間。

Tom’s father died on May 1st, the day before when he had looked pretty well.

改為定語(yǔ)從句結(jié)構(gòu)后，when取代了then, when的先行詞是主句內(nèi)容，而不是May 1st.

2 My uncle works on a farm, and in front of it there is a lake .

這個(gè)句子中的人稱代詞it指代farm。

My uncle works on a farm, in front of which there is a lake .

改為定語(yǔ)從句后，which取代it，which的先行詞為farm。

這就是你問(wèn)的問(wèn)題是什么原因。第一個(gè)定語(yǔ)從句修飾主句。第二個(gè)定語(yǔ)從句修飾farm。