From what I have learned, or I remember I have learned,
哀傷 all mean sadness and are interchangeable. However, as I remember, I have read
哀傷 in academic/professional writings, but not the word
悲哀. On the other hand, I have barely seen
哀傷 used in colloquial context, such as on social networking sites.
Is it the case that
悲哀 is preferred in colloquial context; while
哀傷 are preferred in formal context? Or, if I was wrong, do they actually have different meanings?
Thanks in advance!