This post is not a duplicate of "her dog doesn't even want" vs. "even her dog doesn't want", since that post does not explain why "only" could not be used as an adjective in my second example.
I made up a sentence in another post (Did I put focusing adverbs in the correct position?)
Cambridge Dictionary only has examples about "complete list".
where I used only as adjective, is it still also idiomatic and grammatical if I use only as adjective?
Cambridge Dictionary has only examples about "complete list".
Cambridge Dictionary defines only as adjective
used to show that there is a single one or very few of something, or that there are no others
I guess "there are no others" fits with my 2nd example, only "complete list" no "full list".
I used "only" again (What type of adverbs "also" is?)
I found lots of people using "You can also", more than 1k hits only on ELL. And myself use "also" a lot as well.
and still don't have a clear understanding about its usage.