All languages are confusing for foreigners learning them, or even for small children whose native language is being acquired.
The Danish equivalent of "Put your best foot forward" is "Put your longer leg forward" which makes even less sense then the English expression. After all if your one leg is weaker or shorter than they other obviously you cannot walk fast, which is what these expressions are supposedly encouraging you to do.
Irregular plurals exist in all languages I have ever tried to learn, as do irregular verbs.
Most languages, apart from English, have a completely arbitary system of grammatical gender - Danish has common and neuter nouns with no reference to the actual gender of birds, beasts or mankind. German has three grammatical genders and very few rules accounting for whether a noun is masculine, feminine or neuter.
Formerly, amongst well-educated people there was less confusion about what was correct as grammar was properly taught in schools and even newspapers employed proof-readers, but that is not to say that any of us are less literate than former generations.
It is probably much of a muchness, as nowadays it isn't politically correct to insist on grammatical correctness at the expense of dialects that often are incorrect seen from the grammarian's point.
I was taught that there is a difference between waiting for someone or something and waiting on someone, but all my life I have heard all over the west of Scotland people saying, "I was waiting on the bus for ages." This does not mean they were sitting cosily in the bus, but that they were freezing their bums off at the bus-stop. Fowler's "King's English" (and my father and school-teachers) insisted with one voice that you "waited for the bus" if you were standing at the bus-stop and "on the bus" if it was stuck in traffic or had broken down while you were travelling on it.
