>>cały błąd polega na różnicy między learn i study.
I jeszcze ras grudziu, tu jest problem z aspektem leksykalmnym 'learn'.
Wiesz ze czasowniki angielskie sa podzielone na takie grupy leksykalne ?
Achievement, accomplishment, activity, state ( Zeno Vendler )
Trzeba o tym poczytac, nie wszystkie czasowniki tak po prostu mozna uzyć w present perfect zwlaszcza z niekorymi time adverbilas. Tak samo jak sa takie co nie ‘ida’ z ppc.
I can see the case where we can use the perfective learn with since ‘year’ but it won’t obviously be considered as continuing but rather as completed or incompleted, that’s all.
He has learned only one language since 1987. - completed
He hasn't learned any language since 1987. - incompleted.