昨天回答讀者詢問「學長/學姊」、「學弟/學妹」的英文mentor/mentee，有人提出文鶴出版的「校園美語應用手冊」第336頁，學長/姊：upperclassmen；學弟/妹：underclassmen，比較適合於國內的情況。這點我有所保留。
翻譯不能只是一個蘿蔔一個坑，對號入座那麼單純，不同文化間有時很難有完全對應的翻譯，而且往往要根據上下文來決定怎麼譯。
中文「學長/學姊」、「學弟/學妹」同時帶有親暱及尊敬的意涵，但英文upperclassman主要指美國高中11 & 12年級或大三、大四的高年級生，是中性，有時還帶有貶義。如底下三個例子中的upperclassman是中性，但與中文「學長/學姊」意思、用法不太一樣，若翻成「學長/學姊」也不合適：
I've made it a tradition to go to New York City every fall break, especially since a lot of my upperclassman friends (我高年級的朋友) graduated and went to the city to work. (October | 2011 | University of Rochester Admissions Blog)
I was personally inspired by those early success stories and in my Junior year (大三那年) some friends and I co-founded Vostu…The experience with Vostu marked my upperclassman years (大三、大四那兩年) at Harvard. (www.quora.com/How-entrepreneurial-are-Harvard-students)
I was a sophomore (大二) when IDeATe was first announced and about to go into my upperclassman years (即將升大三). I joined IDeATe on a whim because many of my friends who all had interests in both computer science and art were joining the program. (Calling All Innovators | Carnegie Mellon Office of Admission)
至於upperclassman略帶有貶義的，Urban Dictionary有許多例子，以下為其中之一：
Eleventh Grader: YES! We're eleventh graders! That makes us upperclassmen!!!
Ninth Grader: Uh-ohh... I'm afraid of getting in the way of an upperclassmen (老大)...
還有大學「高年級生宿舍」是upperclassmen dorm；「大一大二生宿舍」是underclassmen dorm；新生宿舍是freshman dorm。但中文不會說「學長/學姊宿舍」或「學弟/學妹宿舍」。注意，高年級生宿舍，大一大二生宿舍的upperclassmen, underclassmen 習慣用複數，但新生宿舍的freshman要用單數。
(Jerome Su, Sept 5, 2018)