【疑問】文頭の Should you ...、疑問文じゃないのに何なん？【TOEIC】

_____ you have any questions, please contact our support team.
(A) Should　(B) Would　(C) Unless　(D) Had
答えは (A) Should らしいんやが、疑問文でもないのに文頭 Should ってなんや

＞＞1
if を省いて、助動詞を前に出した形（倒置）
If you should have any questions ＝ Should you have any questions
「万一〜なら」のかしこまった言い方で、案内文やメールによく出る

＞＞2
後ろは原形なんか

＞＞3
should の後ろやから原形

Should the item arrive damaged, please contact us. の arrive も原形で、arrives にはならん
後半は please ... の命令文や、will の文が普通に来る

見分け方は？

＞＞5
空欄が文頭で、選択肢に Should / Had / Were があって、後ろが「主語＋動詞」、カンマのあとに主節がある。これで倒置を疑う
if と倒置を両方使った If should you ... は誤り

仮定法のおさらいもしたい

＞＞7
今の事実と反対のことは過去形で言う
If we had more staff, we would finish faster.
過去の事実と反対のことは過去完了
If we had known about the delay, we would have changed the schedule.

＞＞8
主節の形もセットか

＞＞9
そう

主節に would have があったら、if 節は had＋過去分詞

Had も前に出せるんやな

＞＞11
If we had known ＝ Had we known
Had we known about the delay, we would have changed the schedule.
be 動詞の were も同じ
If the budget were larger ＝ Were the budget larger

＞＞12
If the budget were の were って、単数やのに was ちゃうんか

＞＞13
仮定法では主語に関係なく were が正式
くだけた会話やと was もよく使われるけど、if を省いた倒置は Were で作るのが普通

＞＞14
いや、Were の倒置なんか実際のメールで見んで。Should の倒置だけ覚えとけばええやろ

＞＞15
よく見るのは Should やけど、主節に would have があったら Had、という判断はすぐできるから覚えて損はない
主節の形から if 節の形を逆算するのが仮定法の基本

if がないのに仮定法になるやつもあるよな。Without とか

＞＞17
Without your help, we could not have finished the project.
＝ If it had not been for your help ＝ Had it not been for your help
主節が could not have finished で、過去の事実の反対やとわかる

仮定法っぽいけど、過去形にならんやつもあった気がする

＞＞19
要求・提案の that 節
The manager requested that the report be submitted by Friday.
request, require, recommend, insist, suggest の後ろの that 節では、かしこまった文だと主語に関係なく動詞は原形（イギリス英語では should＋原形も）
is submitted や was submitted を選ばんように

＞＞20
It is important that ... も同じやったな
It is important that every applicant submit the form on time.
submits にならんのがポイント

文頭の Should / Had / Were、主節の would have、that 節の原形。この3つを見ればいけそうやな