+0
hallo to everyone out there!
Now, my question is when should i use these two expressions. i know both mean surprise, as in "what a nice cat!", but i´m not sure about their different uses and when one is correct and when it´s not.

Anyone out there can help? Big thanks to everyone in advance.
+0
I'm not sure that I understand your question, but "what" can be used to exclaim or enthuse about something, "What a nice cat!"

I was gong to say that "how" cannot be used that way - then I re-thought...
you DO hear some people use it in expressions like "How delightful."
if you wanted to add in the thing you were exclaiming about I think you'd need to add a verb as well,
"How nice that cat is."

But I think that this is idiomatic, not "rules" so you need to look and listen for more real examples.
+0
Anonymous It is interesting to read a dialog that is started in 2003 and ended in 2011 (some people posted 2 years later like what I am doing right now)
Isn't it? Most people don't look at the post dates, so they think they are adding something to a recent conversation. But in reality, the participants are long departed and gone.
Students: Are you brave enough to let our tutors analyse your pronunciation?
Comments  
It is interesting to read a dialog that is started in 2003 and ended in 2011 (some people posted 2 years later like what I am doing right now)
 AlpheccaStars's reply was promoted to an answer.
Students: We have free audio pronunciation exercises.