Question

" 英语科代表“用英语怎么说？

Answer 1

科目＋monitor
e.g. 英语课代表english monitor

Answer 2

In general, 代表 would be translated as representative. But in your case, this title may imply something different since the person may be the best in the subject, and hence may be translated as a "delegate".

也就是说,英语科代表的说法应该是
english delegate

Answer 3

English representative of the class
一般简化为English Rep.

Answer 4

English representative of the class

Answer 5

representative of English class