Yuさんへ
以前のご質問への回答となり恐縮です。
私からはシンプルに伝えるための表現を紹介致します。
How early should I get there?
で、「どれくらい早くそこに行くべきか」
ということで、「何分前」とは伝えていませんが
全く同じ事を尋ねることができます。
あるいは、
Okay, the bus will leave at 7:00.
So, What time should I get there?
というように、what time で尋ねても
同じ事がなんとか聴けますね。
我々日本人が英会話をする時に、表現が出て
こないのは永遠の課題ですね。ニュアンスを
多少削ってでも、確実に相手に伝えられる
スキルが身に付けることが大事であると
個人的には考えております。
（もちろん、きちんと○○前までに、という
表現を学習することも同様に大切ですが）
・・・少しでも参考として頂けますと幸いです。
Yuさんの英語学習の成功を、願っております。
LLD外語学院 学院長 前川 未知雄
How many minutes prior to the departure time should I be arriving at the meeting place?
How many minutes before the departure time should I be arriving at the meeting place?
prior to～=「～より前に」や「～より以前に」の意味となります。
prior toよりは少し砕けてますが、同じ意味合いでbeforeを使ってもかまわないです。
How many minutes prior to the departure time should I be arriving at the meeting place?
出発時間の何分前に集合場所に着いていればよいですか？
3. How many minutes before the departure time do you suggest I arrive?
1. You are asking for a precise time of arrival.
2. You want to know how late you can arrive.
3. You are asking for the precise number of minutes before departure time.
If you are meeting people, asking for a meeting time is a good way to start.
If you are asking a bus driver or ticket agent about when to go to the bus stop, ask them how early you should be.
人と会うときには、まず待ち合わせ時間を聞くのがよいでしょう。
バスの運転手やチケットの取扱店にいつバスの停留所に行くべきかを尋ねる場合は、どのくらい早く行くべきか（how early you should be）尋ねましょう。
How many minutes before the departure should I get there?
How many minutes before the bus leaves should I be there.
*How many minutes before the departure should I get there?- This means you would like to know how many minutes before the bus leaves should you be there?
For example:
A:How many minutes before the departure should I get there?
B:15 minutes should be fine.
How many minutes before the departure should I get there?という例文について
この文は、バスが出発する何分前に到着すべきなのかを知りたいということを意味します。
例えば
A:How many minutes before the departure should I get there?
出発の何分前に到着した方が良いですか？
B:15 minutes should be fine.
１５分が良いでしょう。
What time should I get there for if the bus leaves at 10am?
It is better to ask the person which specific time they suggest you arrive for. However, you could instead say the following:
"What time should I get there for if the (bus/train/event) (leaves/starts) at (insert time)?"
相手に集合時間を明確に聞くと良いです。しかし、以下ように聞くこともできます：
""What time should I get there for if the (bus/train/event) (leaves/starts) at (insert time)?"（もし（バス／電車／イベント）が（何時）に（出発する／開始する）なら、何時にそこへ行けば良いですか？）
example
"Do you have any idea how long it takes to get there?"
or
"Does it take long to get there?"
or
"Do you know how long the journey takes?"
or
"I want to be on time, which bus do you think I should take?"
"Do you have any idea how long it takes to get there?"
そこに着くのにどれくらいかかるかわかりますか？
"Does it take long to get there?"
そこに着くのに長い時間かかりますか？
"Do you know how long the journey takes?"
どのくらいかかるかわかりますか？
"I want to be on time, which bus do you think I should take?"
時間通りに着きたいので、どのバスに乗ったらいいですか？
How long have I to get there before the bus starts off?
How many minutes will I need to get to the train station before the train leaves?
The phrase 'How long have I' is the same as : How many minutes do I have'. What is being asked for is the length of time that one will need to travel to the bus stop before it leaves. In the second question, you have been succinct by asking for the actual minutes.
So, you may ask:
How long have I to get there before the bus starts off?
or
How many minutes will I need to get to the train station before the train leaves?
How long have I'というフレーズは、'How many minutes do I have'と同じ意味です。尋ねている内容としては、出発するどのくらい前までにバス停まで移動していなければならないかという時間の長さです。二つ目の例文では、実際の時間の長さについて簡潔に聞いています。
このように尋ねると良いでしょう。
例文
How long have I to get there before the bus starts off?
バスが出発するどのくらい前に到着してなければなりませんか？
How many minutes will I need to get to the train station before the train leaves?
電車が出発する何分前までに駅に着いていなければなりませんか？
What time do I need to be at the station to catch the bus?
If boarding starts at noon, what time should I arrive?
What is the best time for me to arrive?
I would ask what time the bus left or how early must I be there to board the bus. I would also ask what is the best time to arrive at a party or dinner. Would you tell me the best time to arrive? or Can you tell me how long it takes to travel to the bus station? My bus leaves at noon.
How long is it until (my bus leaves, the train departs, it is time to go, etc)
How many minutes is it before (the bus goes, the meeting begins, etc)
How much time is it until / before ............
You can use "until" to refer to a period of time before something happens. "Long" here refers to a period of time and not the length of something. "Before" refers to the time earlier than a particular event.
how long before departure should i arrive at the bus station?
a casual way to ask this is "what time should i get there?" where as a more formal or specific way to ask this question is "how long before departure should i arrive at the bus station?" both of these questions will suffice.
日本 
イギリス 
カナダ 
南アフリカ 
アメリカ合衆国 
ニュージーランド 
