If you English - born - speakers think its difficult language... you are mistaken. Understanding it ts a matter of having some imagination while using its glorious vocabulary.
There are subtle differences between certain words which can be easy identified out of context, and many times I heard - there are multiple meanings to one word! yes, thats correct, also it makes it easier - one doesn't have to know million ways of saying the same (unless its irony or sarcasm or simply - figure of speech) .
Simplest thing about English and its difficulty... is number of people using it. If it was a difficult language there would be not that many people using it
Also you have one fixed form for all sexes.... well, that makes it easier as well! and lack of other "forms" used in other languages. I am just laughing now, sorry! grammar is to be said to be so difficult cause there are ... erm.. 12 ? ish? tenses ... oh my... some languages go with 3 or even less and are really tricky....
Also, using other language gives perspective to English and one can really make out differences between "complete" and "finished" (Finnish-ed - like soviets in Winter War LOL), "precise", "accurate" and "exact" :D
Also it depends on "posh-ness" of the speaker
all them different meanings and words assigned to social classes..... :D posh - smart, napkin - serviette, settee- sofa etc etc.... Hence, foreigners can have better perception of language than English born speakers as they understand it through their own, hence they can refer back or to other words or meanings used not in English and actually make sense out of it even more than ... language natives
It does not come within a day or two though. It is a matter of years and obviously practice and fun of communicating
And dont get me wrong I do make mistakes, after all its not my original language, but I am really enjoying using it, cause its easier than my own LOL
Cheers