Here is a phrase (slightly modified from the original) that I'd like to discuss.
A) targeting small structures that are hard to distinguish
I have no doubt that this will convey what it means, but I think that the following is more "authentic" in terms of grammar:
B) targeting small structures that are hard to be distinguished
Would you agree or not? Can you explain why grammatically?
I tried to explain why I think B is better, but I'm not sure now.
I think the problem can be simplified to the difference between the following examples:
C) small structures are hard to distinguish
D) small structures are hard to be distinguished
It's about what is the subject for the verb "distinguish". Please help!