語法上 could you play the violin last year?沒有錯
而且,加個 already 意思就更精確了：
Could you already play the violin last year?
不過一個比較習(xí)慣的表達方式是
When did you start playing the violin?
也希望點擊“選為滿意答案”及時采納,可是could you ,,,,好像是委婉語氣，但是這里could you表示過去時態(tài)，這沖突嗎是的， could 有兩個用法， 委婉語氣是其一，過去式是其二， 所以加 already 。could you already 強調(diào)過去式的用法。你也可以說were you already able to play ...但這說有點別扭。