英語で理由を説明する練習｜becauseだけで終わらせない
becauseは言えるのに理由が薄くなる人へ。ANSWER→BECAUSE→PIN→SHOW→RESULTで、vagueな理由を具体化し、必要なら結果まで短くつなげる練習をします。
becauseを別のconnectorに置き換える前に、becauseの後ろを具体化します。vague wordを一つ見つけ、detailを一つ足し、必要ならresultまでつなげます。
I like this café because it’s good.。grammarは大きく壊れていません。でも“good”が何を意味するか分からない。becauseは入口。理由の中身はその後。 because it’s quiet, so I can work there. まで行くと、reasonが見えます。
- ANSWER：結論・出来事を言う
- BECAUSE：direct reasonを置く
- PIN：vague wordを見つける
- SHOW：concrete detail/exampleを一つ足す
- RESULT：必要ならimpactへつなぐ
BECAUSE：まずreasonを一つ置く
Cambridge GrammarのAs, because or since?では、because はreasonをfocusしたいときに非常によく使われるformとして説明されています。because自体を“beginner English”として避ける必要はありません。
- I chose this café because it’s quiet.
- I left early because I was tired.
- I took the train because it was cheaper.
問題はbecauseではなく、becauseの後ろが good、bad、hard だけで止まることです。
PIN：vague wordを一つ見つける
| Weak reason | Vague core | Next question |
|---|---|---|
| because it’s good | good | What exactly is good? |
| because it’s difficult | difficult | What makes it difficult? |
| because I’m busy | busy | What is taking your time? |
| because the traffic was bad | bad | What happened in the traffic? |
ここでconnectorを変えません。まずvague wordをPINして、detailをSHOWします。
SHOW：abstract reasonを一つのdetailに変える
| Before | After |
|---|---|
| I like this café because it’s good. | I like this café because it’s quiet and I can usually find a table. |
| The course was difficult because it was hard. | The course was difficult because the instructions were unclear. |
| I was late because the traffic was bad. | I was late because the traffic barely moved for twenty minutes. |
| I chose the train because it was better. | I chose the train because it was cheaper and went directly to the city centre. |
SHOWは“証拠を提出する”という意味ではありません。ordinary conversationなら、listenerがreasonをpictureできるone detailで十分なことが多いです。
RESULT：reasonが何を変えたかまで言う
Cambridgeのcauses, reasons and resultsでは、because などがreasonを導き、so がcause/reasonのあとにresultを導くpatternが示されています。
- The café is quiet, so I can work there.
- The instructions were unclear, so I kept making the same mistake.
- The traffic barely moved, so I missed the first ten minutes.
CambridgeのWhyでは、That’s why... もearlier reasonからresultへつなぐconversation formとして紹介されています。
The train was much cheaper. That’s why I chose it.
| Direction | Example |
|---|---|
| result → reason | I chose the train because it was cheaper. |
| cause → result | The train was cheaper, so I chose it. |
| cause → result | The train was cheaper. That’s why I chose it. |
because と because of を分ける
Cambridge Grammarのbecause or because of?では、because はverbを含むclauseの前、because of はnoun / noun phraseの前に置くと説明されています。
| Pattern | Example |
|---|---|
| because + clause | I was late because the traffic was heavy. |
| because of + noun phrase | I was late because of heavy traffic. |
reason for / reason why も整理する
CambridgeのReasonでは、reason for + noun phrase、reason why + clause が使われ、reason because はこのpatternでは使わないと説明されています。
- What’s the reason for the delay?
- The reason why I left early was that I felt sick.
4-case reason-expansion lab
A model
I like this café because it’s quiet, so I can work there.
B model
The course was difficult because the instructions were unclear, so I kept making the same mistake.
C model
I was late because the traffic barely moved for twenty minutes, so I missed the first ten minutes.
D model
I chose the train because it was cheaper. That’s why I had enough money left for dinner.
4つのreason practice card
Original practice example
I like this café because it’s quiet, so I can work there.
goodをquietへ具体化し、そのdetailがどう役立つかまでRESULTにつなげています。
placeやserviceの好みを説明する場面。
「このカフェが好きです。静かなので、そこで仕事ができます。」
quietを別のconcrete reasonに入れ替えてください。
Original practice example
The course was difficult because the instructions were unclear.
difficult because hardのようなcircular reasonを、actual causeへ変えています。
class、task、softwareなどのdifficultyを説明する場面。
「そのコースは、説明が分かりにくかったので難しかったです。」
difficultの原因をone observable detailで説明してください。
Original practice example
I was late because of heavy traffic.
because of + noun phraseのclean patternです。
delayやproblemのreasonをshortに説明する場面。
「ひどい渋滞のせいで遅れました。」
同じmeaningをbecause + clauseへ変えてください。
Original practice example
The train was cheaper. That’s why I chose it.
causeを先に置き、That’s whyでresultへ進みます。
choiceやdecisionのreasonをreverse directionで説明する場面。
「電車のほうが安かったです。だから選びました。」
because versionへreverseしてください。
Reason Englishのmistakeも修理する
| Original | 分類 | Listener interpretation | Intent | Natural alternative | Context note |
|---|---|---|---|---|---|
| I was late because traffic. | wrong | trafficがreasonだと分かりますが、becauseの後ろにclauseがありません。 | 渋滞で遅れた | I was late because the traffic was heavy. / I was late because of heavy traffic. | because + clause / because of + noun phrase。 |
| I was late because of there was heavy traffic. | wrong | heavy trafficをreasonにしたい意図は明確ですが、because ofの後ろにfull clauseを置いています。 | 渋滞で遅れた | I was late because there was heavy traffic. | Full clauseならbecause。 |
| The reason because I left was the noise. | wrong | leaving reasonを説明したい意図は分かりますが、reason becauseのpatternが不自然です。 | leaveした理由を言う | The reason why I left was the noise. | Cambridgeはreason why / reason forを示しています。 |
| I like it because it’s good. | grammatically valid with a different meaning | positive evaluationがreasonだとは伝わりますが、goodの具体的中身は分かりません。 | 具体的な理由を説明する | I like it because the examples are short and easy to review. | Originalはgrammar上自然。problemはspecificityです。 |
Final drill：good / bad / hard / busy を一度禁止する
becauseは入口。理由の中身はその後。 asやsinceへ言い換えるより先に、listenerが「なるほど、それがreasonなのね」とpictureできるdetailを一つ置く。それだけでreasonはずっとstrongになります。