"Why B and not A?"
→なぜAではなくBを？
"Why B rather than A?"
→なぜAよりもBを？
似た様な表現ですが、日本語にもある通り若干ニュアンスが異なります。
両方とも、それほど難しい構文ではありません。しかし、日本語とは比較する二つの対象の順序が逆なので注意しましょう。
なお、「なぜ～選んだか」「なぜ～研究したか」など特定の行為について尋ねる場合は、その行為を以下のようにwhyのあとに入れれば大丈夫です。
"Why choose B and not A?"
"Why research B rather than A?"
もし特定な行動がなく、「なぜAではなくBなの？」だけなら
Why is it B and not A?
もし特定な行動があれば（「なぜAではなくBを選んだの？」など）、
Why did you choose B and not A?
Why did you go to England and not America?
You can ask someone their preference in relation to two objects by asking:
Why do you like B instead of A?
What makes you prefer B instead of A?
What made you choose B instead of A?
To like, prefer or choose can be used interchangeably.
I hope that helps!
２つのうち、なぜ片方のほうが好きかという話をするなら、こんな風に聞くことができます。
Why do you like B instead of A?
What makes you prefer B instead of A?
What made you choose B instead of A?
like, prefer, choose は互いに置き換え可能です。
参考になればうれしいです！
Instead' means an alternative or another choice. For example: "I like tea instead of coffee".
'Prefer' is to like something or someone more than another thing or person. For example: "I prefer it when it's hot"
You can also use both in the same sentence: "I prefer to eat early in the day instead of at night"
Instead' とは、代わりの、または他の選択肢のことを意味します。
例文
"I like tea instead of coffee."
「私はコーヒーよりもお茶が好きです。」
'prefer'は、他のものや他の人よりも何か、または誰かのことが好きということを意味します。
例文
"I prefer it when it's hot"
「私はそのものが熱い方が好きです。」
Insteadもpreferも両方同じ文に使うことができます。
"I prefer to eat early in the day instead of at night"
「一日のうちで私は夜よりも早い時間に食べる方が好きです。」
When choosing between two options we often say that you choose one over the other, you can also use the word rather. "Why did you choose B rather than A?"
二つの選択肢から１を選ぶという場合、これはchoose ... over ---ということができます。
または、Why did you choose B rather than A?と尋ねることも可能です。
1. Here you are asking why this person has shown a greater liking for B compared with A. This person should now explain why he made that choice.
2. Here you are asking someone to list the positive aspects of B and so explain why they chose B.
Here you are asking someone about A's bad points and request this person to detail these so as to explain their choice.
example
"why did you choose this college instead of that".
or
"why did you prefer the UK".
or
"which one did you prefer?".
例文
"why did you choose this college instead of that".
なぜあの大学ではなくこの大学を選んだの？
"why did you prefer the UK".
なぜイギリスを選んだの？
"which one did you prefer?".
どちらが好きなの？
*Why do you prefer B to A? - After doing a comparison let's say you have been given 2 options, there's one that you prefer over the other.
A: These are the meat options: beef, chicken, pork
B: I prefer chicken to beef.
*Why choose B instead of A?
A: I thought the pink dress was better than the red one. Why did you choose the pink one?
B: I have a weakness for pink, it's my favorite color.
*Why do you prefer B to A?
どうしてAよりBの方が好きなの？
A: These are the meat options: beef, chicken, pork
ビーフ、チキン、ポークから選べるよ。
B: I prefer chicken to beef.
ビーフよりチキンの方が好きだわ。
*Why choose B instead of A?
どうしてAじゃなくてBを選ぶの？
A: I thought the pink dress was better than the red one. Why did you choose the pink one?
赤のドレスより、ピンクのほうがいいと思ったよ。どうしてピンクを選んだの？
B: I have a weakness for pink, it's my favorite color.
ピンクに弱いの。好きな色だから。
One of your friends likes B more than A, and you want to know why, you can use one of these sentences and they should help you out.
For example.
Why do you prefer B to A?
I don't know I just do.
Fair enough.
I hope that helps.
Have a great day.
Will
アメリカ合衆国 
イギリス 
南アフリカ 
