[化学論文のための英語講座] 第46回：形容詞 Part2

(English version is here.)

形容詞 Part2 形容詞の性質を持っている動詞：現在分詞と過去分詞

現在分詞または過去分詞は形容詞としても使えます。自動詞の場合は現在分詞を利用し、他動詞の場合は過去分詞を使います。例えば、英語の「stack」は名詞でもあり、自動詞としても他動詞としても使えます。以下の例文を見てみましょう。

1. In some complexes the stacking angle is about 30°.
2. In some complexes the stacked angle is about 30°.
解説：両者は正しくて意味はだいたい同じですが、例文１は進行している印象を与え、例文２は完了した印象を与えます。

同様に「result」も名詞であり、自動詞としても使えるので現在分詞の形で形容詞の役を果たします。次の例文を見てみましょう。

3. The resulting enolate was reacted with the appropriate electrophilic partner.
解説：「result」は自動詞なので、ここで過去分詞の「resulted」を利用するのは間違いです。

「obtain」は他動詞なので、形容詞として使う場合は過去分詞を利用します。次の例文を見てみましょう。

4. The obtained crude product was recrystallized to give purple crystals suitable for X-ray crystal diffraction analysis.
解説：ここに「obtaining」を利用するのは間違いです。

次回は「形容詞 Part3」です。

Adjectives 2 Verbs with adjective characteristics: present and past participles

Present participles as well as past participles can be used as adjectives. In the case of an intransitive verb the present participle is used, and with transitive verbs, the past participle is used. For example, the word stack is a noun, and can also be used as both a transitive and intransitive verb. Let us look at the following examples.

1. In some complexes the stacking angle is about 30°.
2. In some complexes the stacked angle is about 30°.
Explanation: Both are correct and largely have the same meaning, however, sentence 1 gives an impression of continuation, whereas sentence 2 gives an impression of completion.

In the same way, the word result is also a noun, and can be used as an intransitive verb in the present participle form serving as an adjective. Let us look at the following example.

3. The resulting enolate was reacted with the appropriate electrophilic partner.
Explanation: Result is an intransitive verb, thus using the past participle resulted here would be a mistake.

The word obtain is a transitive verb, thus when using as an adjective the past participle is used. Let us look at an example.

4. The obtained crude product was recrystallized to give purple crystals suitable for X-ray crystal diffraction analysis.
Explanation: Here, using obtaining would be a mistake.

At next time, we will discuss Adjectives 3.