ENGLISH IS NOT DIFFICULT TO LEARN..."IT'S THE NEXT" (LO SIGUIENTE)
I can't remember whether I have ever heard a Spanish speaker use this phrase but I hear it quite often when Spanish speakers are speaking Spanish so I am sure there are lots of people who (in their minds) are trying to find a quick translation for it.
Clearly, the version above is the Spanglish version and should be avoided if possible!
One way to avoid the problem altogether is by not using the negative form and just saying: "English is very very difficult to learn".
Another option might be: "English is not difficult to learn...It's extremely difficult to learn".
Hope that helps!
Soy el director de Daniel Smith + Partners. Tengo más de 15 años de experiencia enseñando inglés a españoles.