[化学論文のための英語講座] 第72回：動詞の時制についての復習 Verb tense review
2024年12月2日
(English version is here.)
今回は動詞の時制の復習です。以下の例文に下線で指示されている表現を、時系列で確認してみましょう。
(注)アルカロイドYVR、植物YYZとNRT、中間体KIXは架空のものであり、対象文法を示すためだけに使用しています。
1. For the past few years, A. we have focused efforts towards the total synthesis of YVR alkaloids with particular emphasis on routes that allow for late-stage elaboration at the C17 position as well as selecting presence or absence of a double bond between C5 and C6. This flexibility B. would allow preparation of various analogues via a common advanced intermediate which C. could then be utilised in further studies.
和訳：近年、我々はYVRアルカロイドの全合成に向けて努力を集中してきました。特に、C17位での後期段階の精製を可能にする経路と、C5とC6間の二重結合の有無を選択できる経路に重点を置いています。この柔軟性により、共通の高度な中間体を介してさまざまな類似体を調製できることになり、その後、さらなる研究に活用できるようになります。
回答：A. we have focused は過去時点から現在まで続いています。For the past few years/weeks/days が現れる時は現在完了形をよく使います。ここではB. would と C. could と一緒に現れますので仮定未来だとわかります。
2. YVR A. was first isolated from YYZ, an annual, dioecious, flowering plant indigenous to temperate to subtropical regions of East Asia. This B. had been thought to be the only natural source of YVRs C. when it was serendipitously discovered in an extract of NRT, an unrelated plant native to the Iberian Peninsula.
和訳：YVRは東アジアの温帯から亜熱帯地域に自生する雌雄異株の一年生顕花植物であるYYZから最初に単離されました。YVRがイベリア半島原産の関係のない植物であるNRTの抽出物として具然発見される時点まで、YYZはYVRの唯一の天然源であると考えられていました。
回答：A. was first isolated は過去の一時点です。序数（first, second etc.）が現れると過去形がよく使われます。B. had been は過去の時点で続いていた過去に終わった状況です。過去完了形で表す出来事や状況はいつも関係のある過去の他出来事や状況と現れます。C. when it was serendipitously discovered は過去の一時点です。
3. Initially, we A. focused on ring-closing metathesis approaches to form the eleven-membered ring structure, but B. were plagued by low yields. As an alternative, we then C. explored the Nozaki-Hiyama-Kishi reaction and D. were pleased to find that it E. gave consistently satisfactory results. We F. have optimised the reaction conditions for our substrates and G. utilise this reaction for preparation of advanced intermediate KIX.
和訳：当初、我々は11員環構造を形成するために閉環メタセシス法に重点を置きましたが、収率が低いという問題がありました。そこで代替策として、野崎・檜山・岸反応を検討し、一貫して満足のいく結果が得られることを知り、喜ばしく思いました。我々は基質に対する反応条件を最適化し、この反応を利用して高度な中間体KIXを調製しました。
回答：A. focused は過去の一時点です。「Initially」は一時点なので過去形が適切です。B. were plagued と E. gave は過去形です。F. have optimised は現在完了形で、最適化済みです。G. utilize は一般的な行為で現在形です。
時制の図に入れると以下のようになります。
*1: 例文1C, 2A, 2C, 3A, 3B, 3E
*2: 例文1A
*3：例文2B, 3F
*4：例文3G
次回は前置詞に関してです。
We will review verb tenses. Let us check the underlined expressions in the following sentences in chronological order.
Note: Alkaloid YVR, plant YYZ and NRT, and intermediate KIX are imaginary, and are used only to demonstrate the target language.
1. For the past few years, A. we have focused efforts towards the total synthesis of YVR alkaloids with particular emphasis on routes that allow for late-stage elaboration at the C17 position as well as selecting presence or absence of a double bond between C5 and C6. This flexibility B. would allow preparation of various analogues via a common advanced intermediate which C. could then be utilised in further studies.
Answer: A. We have focused continues from a past timepoint to the present. When for the past few years/weeks/days appears the present perfect is often used. Because B. would and C. could appear together, a hypothetical future is understood.
2. YVR A. was first isolated from YYZ, an annual, dioecious, flowering plant indigenous to temperate to subtropical regions of East Asia. This B. had been thought to be the only natural source of YVRs C. when it was serendipitously discovered in an extract of NRT, an unrelated plant native to the Iberian Peninsula.
Answer: A. was first isolated is a single point in the past. If an ordinal number (first, second etc.) appears, the preterit (simple past tense) is often used. B. had been continues from a point in the past to a termination point in the past. Events or conditions shown in the past perfect always appear in relation to another past event or condition. C. when it was serendipitously discovered is a single point in the past.
3. Initially, we A. focused on ring-closing metathesis approaches to form the eleven-membered ring structure, but B. were plagued by low yields. As an alternative, we then C. explored the Nozaki-Hiyama-Kishi reaction and D. were pleased to find that it E. gave consistently satisfactory results. We F. have optimised the reaction conditions for our substrates and G. utilise this reaction for preparation of advanced intermediate KIX.
Answer: A. focused is a single point in the past. Initially is a single timepoint so the preterit (simple past tense) is appropriate. B. were plagued and E. gave are preterit. F. have optimised is present perfect, and optimisation is complete. G. Utilise is a general activity or occurrence and is preterit.
Each underlined part in the above example sentence is represented in a tense diagram as follows:
*1: Example 1C, 2A, 2C, 3A, 3B, 3E
*2: Example 1A
*3：Example 2B, 3F
*4：Example 3G
At next time, we will post about preposition.