Chapter3. Planning for the Perfect Wedding-grammar-

正：that is the same person that asked for help the day before yesterday.
題解：先行詞有the same修飾時，一般用as，如：he uses the same dictionary as i do.（他用的詞典和我的一樣）但要注意的是，這句中涉及到兩本字典。如果指的是同一個人或物，先行詞應該用that。
例13  誤：my mother often takes on more work than it is good for her health.
正：my mother often takes on more work than is good for her health.
題解：此句中包含了一個由than引導的定語從句。因先行詞work有形容詞的比較級修飾，因此關系代詞用了than。而此句中的先行詞work在定語從句中作主語，所以從句中處于主語位置的it必須刪去。
例14  誤：mr. white is the man whom you can turn for help when you are in trouble.
正：mr. white is the man to whom you can turn for help when you are in trouble.
題解：先行詞man在定語從句中應該作介詞to后的賓語，turn to sb. for help，所以此處的介詞to不能少。因此，定語從句中介詞的選擇受到上下文的制約或與前面的名詞詞組或后面動詞詞組的搭配有關。
例15  誤：is this book you like most？
正：is this the book you like most?
題解：若把原句改成陳述句，“this book is you like most.”不難發現它不是一句定語從句，this book也不是先行詞。加了定冠詞后，此句改成陳述句就成了：this is the book you like most.先行詞book在從句中作賓語，所以可以省略關系代詞。 
例16  誤：i can think of many cases that students obviously know a lot of english words and expressions but couldn’t write a good essay.
正：i can think of many cases where / in which students obviously know a lot of english words and expressions but couldn’t write a good essay.
題解：先行詞case若放回定語從句中，應是in many cases，作狀語，故應用關系副詞where，或in which。
例17  誤：last year he visited tokyo where his brother lived.
正：last year he visited tokyo, where his brother lived.
題解：限制性定語從句與先行詞關系密切，對它有限制作用，因此不可缺少，否則會影響全句的意義。而非限制性定語從句是對先行詞的補充說明，他們之間的修飾關系不是很密切，因此對于專有名詞，一般都用非限制性定語從句。
例18  誤：he has many habits, some of them are harmful.
正：he has many habits, some of which are harmful.
題解：原句錯在一個句子中出現了兩個簡單句，且無連詞。用which代替them，使后面的分句變成了非限制性定語從句，which 指代前面的habits。此句若改成如下句子亦可：
           he has many habits, and some of them are harmful.
例19  誤：she got the first prize, which we had expected.
正：she got the first prize, as we had expected.
題解：雖然，在非限制性定語從句中，which可以用來指代前面的整個句子，但當表示 “正如”時，一般用as，此外，as引導的非限制性定語從句還可放在主句之前，而which不行。