I freely admit it's not very likely, but I thought I'd throw it out there.
I believe most Japanese learners of English have trouble understanding things pertaining to the singularity or plurality of English noun. I think there are at least two reasons for that:
(1) Japanese nouns have no inflected forms. (I do not refer to the exceptions here.) For instance, both of "book" and "books" correspond to the same Japanese word
hon.
Hon might be translated several ways in English when it is used in contexts:
hon = a book/the book/some books/the books/his book/his books/books in general/etc.
(Please note that the Japanese language does not have any equivalent of "a", "an", or "the".)
(2) Japanese teachers of English tend to steer clear of tricky matters concerning the singularity or plurality of English noun. The same thing holds true for Japanese authors/producers/developers of English teaching materials, I might add.
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The Japanese language is in stark contrast to the English language in many ways. To me, English is
a million miles away from Japanese. Thus, there are a fair number of situations in which what a native English speaker thinks is obvious is
in no way obvious to Japanese learners of English. To me, it seems as if most Japanese learners of English were doomed to have excruciating experiences in the process of learning English as long as they were serious learners. In that sense, your answers/comments are immensely helpful to me.
Thanks, Skrej.