Originally Posted by: KLZ39

I was looking some music sheets i found somewhere around and i saw something that confuse me

This could be cleared up with a picture of the notation question. Maybe you can find a way to upload an image?

It sounds like you are looking at some kind of syncopated rhythm with tied eighth notes that actually last the duration of quarter notes. Something like this:

That pattern has a quarter note, but you can get the idea of what I mean by the rest of the measure. Hope that helps!