From Twitter:
答えは？Fill in:
The book __ is on the table, __ was written by Sam Harris, is excellent.
a. what
b. that
c. which
日本語訳
Twitterより。穴埋め：「テーブルの上にある、サム・ハリスが書いた本はすばらしい」。what / that / which から、二つの空欄に入る語を選びます。
The solution is to add that first and which second:
The book _that_ is on the table, _which_ was written by Sam Harris, is excellent.
Explanation:
Generally, that defines and which describes. This means that what follows that is essential to the completion of the idea and defines the subject; what follows which is extra information describing the subject and not necessary to the main idea.
That
1. In the sentence above, that tells us exactly book the speaker is talking about: the one on the table. This information is essential, because other books are probably in the room or being considered. So it's not merely 'the book'; it's "the book on the table". That is the full "name" of this book for the purposes of the sentence.
2. Also in the sentence above, notice there is no comma after that.
Which
3. In the sentence above, which refers back to the subject: the book on the table with extra information about it: that it was written by Sam Harris. This is extra information to add for interest or detail, but it is not necessary for explaining what the speaker has to say--namely that there is a book on the table and that it is excellent. It's like saying:
The Martian, which was written by a technician and non-professional writer, was a blockbuster movie.
The point is The Martian was a blockbuster; that it was written by a technician, though very interesting, is not the point.
4. Which clauses containing additional information are enclosed by comas. Think of what is in there (between the comas) as words that could easily go inside parentheses:
The book that is on the table (which was written by Sam Harris) is excellent.
The Martian (which was written by a technician and non-professional writer) was a blockbuster movie.
5. That clauses adding essential and defining information to the subject are not enclosed in commas and so could not be enclosed in parentheses.
The book that is on the table is excellent. (there is no place for commas!)
6. Finally, just remember: If you are thinking about adding information to a sentence about the subject, but you could leave that information out without losing the main meaning (of the main clause/the independent clause/the main idea) use which. If you cannot, use that.
Link: http://samharris.org
解答・解説の日本語訳
順に that、which。完成文は「テーブルの上にある、サム・ハリスが書いたその本はすばらしい」です。一般に、that は対象を限定し、which は追加情報を説明する、と筆者は整理しています。that is on the table は「どの本か」を特定する不可欠な情報です。部屋にほかの本があるかもしれないので、ただの「その本」ではなく「テーブル上の本」と言う必要があります。この that 節はコンマで囲みません。which was written by Sam Harris は本の著者について付け加える説明で、主旨「その本はすばらしい」に不可欠ではないためコンマで挟みます。「『オデッセイ』は大ヒット映画だった。技術者で専業作家ではない人が原作を書いた」という例も、映画の成功が主旨で、原作者の説明は補足です。補足説明は「テーブルの上の本（サム・ハリスの著作）はすばらしい」のように括弧の中へ移しても主文の意味が通ります。一方、「テーブルの上にある本はすばらしい」の that 節を外すと、どの本か特定できなくなります。主語についての説明を省いても中心の意味が保てるなら which、省くと意味が変わるなら that を目安にします。原文は関係節の制限用法と非制限用法を説明しています。