What's difficult really depends on the languages you already know.
In addition to noun inflection, verb aspect, pronunciation stress, and punctuation trouble many native English speakers. That's in addition to all the simple irregularities, like irregular nouns and verbs.
Stress even troubles native speakers. When I lived there, I saw slideshow "where 's the stress?" quizzes used to fill time on screens in taxi buses, waiting rooms, and the like.
In addition to noun inflection, verb aspect, pronunciation stress, and punctuation trouble many native English speakers. That's in addition to all the simple irregularities, like irregular nouns and verbs.
Stress even troubles native speakers. When I lived there, I saw slideshow "where 's the stress?" quizzes used to fill time on screens in taxi buses, waiting rooms, and the like.