I was recently corrected by a Chinese friend. He said it's incorrect to say:
He said the right form is:
Which sentence structure pattern is this following. Is it used with only certain verbs? Only with 能／可以／会？
I'm not able/ allowed/ permitted/ qualified to look for something/somebody.
I am not able to/ cannot find the things that I am looking for.
Typically, native speaker seldom use "我不能找".
English speakers don't quite say "I cannot look for something" either, right?
Um, in your description you had two identical sentences… Let's go with your title.
"我不能找" is wrong. It conveys either that "I am not allowed to search" or "I do not possess the ability to search."
"我找不到" is the correct way. It means "I searched, but cannot find."
Note the nuance between not able to search ("不能找") and not able to find ("找不到").