如何分辨副詞子句裡的獨立子句和從屬子句？

Question

我想要知道為什麼是用where來當做這四句裡面的從屬連接詞，而且為什麼是這樣寫？要靠什麼樣的方法才能分辨出副詞子句裡的獨立子句和從屬子句？

例如：
Consumers have a tendency to buy more where credit cards are accepted for payment of merchandise.
You cannot use credit cards where you shop.
There are a few places of business where a credit card is not accepted.
Travelers can use credit cards in foreign countries where they are accepted.

因為我實在是不清楚為什麼是這樣寫，希望知道的人能幫我解答，謝謝！

Answer 1

where 後面一定是接從屬子句
用這個子句來形容這個地方或是提供更多細節
1. 客人通常會選擇可用信用卡付費的商店大量消費
where後面就是在說明怎樣的商店讓客人更願意花錢買東西
2. 你消費時不能用信用卡
where有點限制的意味~~你不能用信用卡買東西(要看上下文而定)
3. 很少商店是不接受信用卡付費 (也就是大部分商店都接受信用卡付費)
where此時代表先行詞 a few places of business
4. 旅人在入境後可以在那個國家使用信用卡
where指的是foreign countries 也就是旅人可入境的國家
希望多少能幫你一點忙囉~~

Answer 2

首先, 用一個簡單的例子:
I live where I work.(我住在我上班工作的地方)
where所引導的子句, 當副詞用, 表示地方. 更簡化來看:
I live in Taipei.
I live here.
基本結構: 主詞(S.)+動詞(V.)+副詞(Adv.)
畫底線的部分, 功能都一樣, 只是以不同的型態(子句, 片語, 單字)呈現, 端看你要的表現方式.
Consumers have a tendency to buy more where credit cards are accepted for payment of merchandise.
(在可以刷卡的地方, 消費量容易增加)
S: consumers
V: have a tendancy to buy more(動詞相關字群)
Adv: where...

您問: 為什麼是用where來當從屬連接詞, 其實不見得
看您要表達什麼意思:
Consumers have a tendancy to buy more when credit cards are accepted for payment of merchandise.
(當刷卡觀念普及時, 消費量容易增加)
You cannot use credit cards where you shop. 結構是一樣的.

再說另外一個用法:
This is a park where you can take a walk.
where所引導的子句, 當形容詞用, 說明park的特性.
There are a few places of business where a credit card is not accepted.
(有些地方是不能刷卡的)
Travelers can use credit cards in foreign countries where they are accepted.
(外出旅遊的人可以在國外那些接受信用卡的地方刷卡)

其實, where所引導的子句, 也可以當名詞用:
Where I live is not important.
I can't remember where he lived.

2006-10-12 21:45:40 補充：
倒數第七行訂正: 有些營業場所是不能刷卡的