What is called "syntactically correct"?

Hello! I run into a thread here, and Mod. Anglika commented on a sentence as "It is fine, both grammatically and syntactically."
http://www.usingenglish.com/forum/as...e-correct.html

What is called "syntactically correct"? I looked up a dictionary, and learned it is about the grammatical arrangement of words in a sentence. I'm not sure I've understood it well.

Here's an example. Is the mistake of original sentence called syntactical mistake?

Original: Mr. Chen was very strict with himself and his children as well. He could often catch opportunities to teach them how to do properly with tactful skill.

Corrected: Mr. Chen was very strict with himself and his children as well. With tactful skill, he would often take the opportunity to teach them how to do things properly.


Many thanks!

PS. I start this new thread because my question is irrelevant to the subject of that one.

Just as to how to understand syntactically:

If the sentence is syntactically correct, it means that the grammatical arrangement of words in the very sentence is correct.

Eg I really am not happy to be there. That one is not correct because really is wrongly placed.
Eg I am really not happy to be there. This one is correct because really is well placed.

This is just a matter of place of the words in a sentence.


Not a teacher at all, though

Philadelphia,

Merci! I've understood.:-D