間接的な yes-no 質問を報告 whether if または報告するかどうかを使用できます。 or で質問します。 If は whether よりも一般的です:

Call the bakeries around town and find out if any of them sell raspberry pies.

I rang Peter from the station and asked if I could drop in to see him before going back or if he’d meet me.

多くの場合、よりフォーマルなコンテキストで次の whether を好みます。

The teachers will be asked whether they would recommend the book to their classes.

【商談会より】

John read a letter that he’d written and the board discussed whether it should be mailed.

間接的な質問に複数の選択肢がある or whether 場合に優先します。

After the election, we asked whether the parties should change their leaders, their policies, or both.

代替を表現するために、 if および whether で or not を使用できます。エンドポジションか直後 whether 使える or not whether か。終了位置のみで使用する or not if を指定します。

I called Bill to find out whether or not he really did go to Afghanistan.

I called Bill to find out whether he really did go to Afghanistan or not .

I called Bill to find out if he really did go to Afghanistan or not .

to 不定詞の前に if と if を使用します。将来の計画や whether について言及する場合によく使用されます。

I was wondering whether to go for a swim.

Some financial decisions, such as planning a pension, need to be taken as early as possible. Others, such as whether to move house, can probably only be made much later.

前置詞の後に whether と if を使用します。

Later I argued with the doctor about whether I had hit my head, since I couldn’t remember feeling it.

Not: Later I argued with the doctor about if I had hit my head …

The police seemed mainly interested in whether there were any locks on the windows.

否定: The police seemed mainly interested in if there were any locks …

疑いの動詞の後に句を導入する場合は if または whether を使用します。

I don’t know if I can drive. My foot really hurts.

I didn’t prune the rose bush this year so I doubt if we’re going to have many flowers. （「プルーン」は切り戻すという意味です）

We’ll have plenty of photographs to show you but I’m not sure whether we’ll be able to learn very much from them.

• -不定詞の前 to if では whether 、 if を使用します。

I don’t know whether to buy the blue one or the red one.

Not: I don’t know if to buy the blue one …

• if ではなく if 、直前 or not whether を使用します。

Can you tell me whether or not you’re interested in the job.

Not: Can you tell me if or not you’re interested …

• if では whether if を前置詞の後に使用します。

【1年間のオーストラリア旅行について語る】

We’re not interested in whether we get great jobs and that kind of thing, we just want to have a good time.

Not: We’re not interested in if we get great jobs and that kind of thing …