My mother tongue is English. I studied Japanese to degree level so I feel at least moderately qualified to comment on it.
English is grammatically fairly simple, having dispensed with much of the (redundant) complexity found in its European brethren (gender, case, almost all inflection). I would argue that that makes it fairly easy for beginners to develop a basic command of it. Its main problems are its unpredictable spelling (does any other language come close? French is a bit of a mess, but nowhere near as bad as English) and its love of a phrasal verb (what do get up/on/down/over have to do with each other?).
English is grammatically fairly simple, having dispensed with much of the (redundant) complexity found in its European brethren (gender, case, almost all inflection). I would argue that that makes it fairly easy for beginners to develop a basic command of it. Its main problems are its unpredictable spelling (does any other language come close? French is a bit of a mess, but nowhere near as bad as English) and its love of a phrasal verb (what do get up/on/down/over have to do with each other?).