Monday-morning quarterback
事後諸葛亮，馬後炮
(字面意思：周一早上的美式橄欖球四分衛)
【解釋】
someone who is always criticizing and saying how he would have done something better or differently after the event has passed
【來源】
(1) During American football season, many American football teams play on Sundays. So, on Monday morning, sports commentators and football fans discuss what happened the day before as if they were the quarterbacks.
在美國橄欖球賽季，許多球隊在星期天比賽。所以，周一早上，體育評論員和球迷們就像四分衛一樣討論前一天發生的事情。
(2) The quarterback leads the team. He talks to the team on the field and decides what actions the players will take to win the game.
四分衛領導球隊，他在球場上與球隊對話，並決定球員將採取什麼行動來贏得比賽。
【例句】
Social media seems to have turned everyone into a Monday- morning quarterback / whenever political issues are discussed.
每當談到政治問題的時候，社交媒體似乎把大家都變成了馬後炮。
Hindsight is (always) 20/20.
事後諸葛；馬後炮 (貶義)
經歷過才明白
(褒義，類似於吃一塹，長一智)
也可說
sb's hindsight is 20/20或者sb has 20/20 hindsight.
【解釋】
1.If your eyesight is normal, you have 20/20 vision. 如果你的視力正常，就是20/20。
2. hindsight /ˈhaɪndˌsaɪt/ n. 後見之明，事後的領悟
【例句1】
A: I can't believe I was ever interested in such a self-absorbed jerk.
B: Don't blame yourself. Hindsight is 20/20, after all.
A: 真不敢相信我之前竟然對這麼一個自私的笨蛋感興趣。
B: 不怪你，畢竟，經歷過才知道。
【例句2】
A: He told me that you shouldn't have done it that way.
B: Well, he definitely has 20/20 hindsight.
A: 他跟我說你不應該那樣做的。
B: 額，他鐵定是馬後炮。