Hi Luke,
Thank you for explaining. I got it clearly

But I am still confused with when to use the restrictive clause. During my mistakes,when I used the general clauses,you corrected it with restrictive clause or nonrestrictive clause. Sometimes I used the adjective clause and then you corrected it with general clause. So I am confused.

Don't mind,I am not complained with that.I think it need both time and more practice to know clearly.

BTW, I didn't find the function to dig all the posts I have posted so that I couldn't give the examples to explain my puzzle. Is it only my trouble in looking for the whole posts or there is not the function in the website?
Jane