To this very day I can't hear the difference between e.g. "sit" and "seat", or "eat" and "it". I can pronounce them no problem, but hearing it? Nope, those two are the same sounds. Well, whatever, the context is always disambiguating enough.

But I can hear the difference between short/long (as in, differing in actual temporal duration) vowels just fine, e.g. in Finnish/Latvian ― although those languages kinda overextend it IMHO.

I've actually messed with Audacity once, extracting the vowels, lengthening them and overlaying, and there is definitely a difference in quality (the length is pretty much the same), it's just that it's very minor to my ear. But native English speakers apparently can pick them up with little trouble.

The difference is much easier to spot in pairs like "bead"/"bid", but that's mainly because before the voiced consonants the long vowel is actually longer than the short one, and the speakers usually add a small glide of "y" at the end of it, so it's more like "beeyd".

I had a native English coworker who used to pronounce it Ü-Bahn and when corrected he insisted that it sounded exactly the same then when I said U-Bahn.

He was perfectly capable of making the same (German) u sound when saying other English words. Apparently it is very subtle, sometimes even for specific things like start of the word and length of the vowel. I just don't know.

I had a teacher of German with whom we learned the rules and drilled just articulating sentences, and in that half year my progress was enormous. Then me and he got busy, he didn't teach anymore. And I see you indeed can learn and improve German to level C if you're lucky to have a good teacher.

I can compare that to Goethe institut's intensive courses: 6 weeks by these fancy colorful textbooks. Waste of time.

> Italian is also very easy to learn

If your native language is similar, for example, Romanian or Spanish, sure it is. For the others, not really.

> while German makes absolutely no sense.

Mark Twain also complained about it.

> A turnip is female, the fishmongers wife is neutral, a boy is male, a girl is neutral, the wife is female. Plural of Tür is Türen plural of Öffnung is Öffnungen, plural of Vogel is Vögel plural of Fenster is.. Fenster.

So as in basically every language that has a grammatical gender. If it's not the same as in your native language, it won't make sense, and you'll need to learn it. After some time, you'll notice the pattern and will be able to guess accurately.

> Hundreds of unspoken rules regarding word order, some verbs that can be separated and others cannot.. Completely random.

The rules are well understood and clearly written. You just need to learn them.

> And good luck even being able to hear the difference between spucken and spuken if your language doesn't have long vs. short vowels.

Isn't that the case about every foreign language? I was never able to distinguish or pronounce correctly French diphthongs. I'm pretty sure half of the people here wouldn't be able to pronounce a couple of sounds from my native language even if their lives depended on it.

French shares those, and add the fact that many letters aren’t pronounced, but must be known to correctly make the "liaison".

The same is true for English in addition that written and spoken English are mostly 2 different languages with very little connection