a couple of sentences

I'll show you four sentences and the evalutation a Korean tutor made to each of them.

1. The scientific opinions of Korean audiences are advanced.
2. Scientific literacy of Korean observers is highly developed.
3. Korean audience have pretty good understanding on sciences.
4. Korean audience has high scientific knowledge.


These are the sentences given to the tutor, and
the comments he made are as follows :

1. The scientific opinions of Korean audiences are advanced.
-> Perfect. Great.

2. Scientific literacy of Korean observers is highly developed.
-> Scientific literacy => The scientific literacy
===============================================
HE IS RIGHT ABOUT THE FIRST 2.



3. Korean audiences have a pretty good understanding of the sciences.
-> have = > has
pretty good understanding => a pretty good understanding
sciences => science

4. Korean audiences have
well developed scientific erudition.
high scientific knowledge.
-> high => a high level of

How would you evaluate the tutor's corrections?
Is he surely as good as native speakers?

Would most native speakers also make similiar corrections
just like he did?

I'd appreciate your comment.
Thanks.