I am not a perfectionist,
and I am not a native English speaker, like it or not.and I will never ever be a native English speaker, no matter how close it will be after years and years endeavor on English learning.
I can not guarantee a hundred percent that my paragraph are mistake-free from both grammar and spelling perspective.
and make sure my paragraph are genuin euough not to misleading kids to bad Chinglish.
the standare is wee bit too high for me.
should I zip my mouth in order not to make mistake?

[ 本帖最后由 nice妈妈 于 2009-3-18 12:14 编辑 ].

I  am not deliberately picking your typo, but here in this sentence "But they would not like to psend lots of time to correct our mistakes that we are making....",it is obviously that you have miss-typed the word "spend",
I am not saying that the spelling is a problem, I just feel that, technically, we are human being, we are prone to all sorts of mistake, is that really a big problem?
some people said, lauguage is for communication, mistake should always be the second focus not the first..

That will be a big favor to all of us.
From my feeling, when I read an English sentence, I will just use my intuition to see whether I could understand it or not, I don't really check out it from a grammar book.
for example, in your sentence, "Sure,its not problem", I would just feel it could be better to say "Sure,its not a problem", for me, the artical word "a" is just an intuitive.
another example "I said i want invite some native English speakers ", I would feel  it could be better to say "I said i want to invite some native English speakers ", to add the preposition "to", is just from the feeling as well.
just to cite a few,
therefore, I am really doubting that :"is the grammar that important", or it may just foster from practice?
I am not an English educator, but I do doubt the way of learning English through grammar. or paying too much attention on the spelling..

Take it easy, you know the old saying "practice makes it perfect", if you don't even practice it, you will never move into a right direction.
But I do feel, to be more cautious about the spelling is harmless, since it is a problem that you may have to face eventually.
so,Don't stumble your pace of practice, and try your best on the grammar and spelling.

[ 本帖最后由 nice妈妈 于 2009-3-18 14:28 编辑 ].

Bravo.