許可の表現

*If you finished early, you might go.

【和訳】

もし早く片付いていたのなら帰ってもよかったのです。

If you finished early, you could go.

【要点】

非現実的文脈では話者の許可を表すmayを使うことはできない。Palmer (1974).

【類例】

1) If you finish early, you may [*might] go.

2) You were free yesterday. You might have helped me with my work.

3) A: Might I (possibly) come in? 

  B: Yes, you may [*might]. / No, you may [*might] not.

4) He said I might go if I wished. ← He said, "You may go if you wish."

【出典】

荒木一雄（編）(1986) 英語正誤辞典　研究社出版　pp. 290-291.