請告訴我 「順便這個也麻煩你了，這句要怎麼用英文說？」 的英語！

・While you're at it, could you also do this for me?
・Since you're already helping, could you also do this for me?
・As long as you're in the process, could you also take care of this for me?

Since you're going to the post office, could you also mail this letter for me?
「既然你要去郵局，可以順便幫我寄這封信嗎？」

「While you're at it, could you also do this for me?」的意思是「你在做那件事的時候，也可以順便幫我做這個嗎？」這是在請求別人幫忙時會用到的表達方式。當你突然想到其他任務或想請對方幫忙做其他事情時，這是一個很方便的說法。不過，還是要考慮對方的負擔，並在適當的時機使用。

Since you're already helping, could you also mail this for me?
「既然你已經在幫忙了，可以順便幫我把這個寄出去嗎？」

As long as you're going to mail some things, could you also take care of this letter for me?
「既然你正好要寄一些東西，可以順便幫我處理這封信嗎？」

「Since you're already helping, could you also do this for me?」是用在對方已經在幫忙的情況下，想要再請對方幫忙做其他事情時。「As long as you're in the process, could you also take care of this for me?」則是用在對方正在進行某個特定事情時，想要再加上一個相關的任務。基本上，前者是針對正在幫忙的事情再提出額外要求，後者則是針對進行中的事情再提出額外要求。

有幫助｜0

・Please do -, while you are at it

「順便幫我這個」的英文可以用
「Please do -, while you are at it」表達。

Please do - 是「請做～」

while you are at it 是「當你在做某事時」
這是直譯，不過這裡有「順便」的意思。

使用範例
「Please post this letter too, while you are at it」
（意思：順便的話，也請幫我寄這封信。）

有幫助｜0