The Awful German Language (1880)

As someone who studied German at school and has made serious attempts to learn Finnish and Czech, I have feelings about this. Obviously Twain was being humourous. But I took three years of German two decades ago, and to this day it is easier than Czech (I'm embarrassed to say, as I've lived here and tried to learn on and off for the last six years). I'm exaggerating only a bit.

The main difficulty with most Slavic languages are the grammatical cases/declensions/etc. German does have conjugations, but they have less forms and there are easily noticeable patterns (at least compared to something like Slovene: https://en.wikipedia.org/wiki/Slovene_verbs#Full_conjugation...). The words might seem scary, but actually require less thinking to use in sentences.

It's not so much the cases but the interaction with cases and gender. I found Finnish easier in some ways, despite the many cases. Because the case endings are always the same (modulo vowel harmony) so you can extract helpful information - something is inside something else say. In Czech a word ending with u has five different possible gender-case combinations (if I counted right) and that's not counting the distinction between short and long u.

I'm a Polish speaker and have met some Polish learners in my life. Often I have no better advice than "you choose the conjugation patern based on how does the word feel to you".

Writing as a native Slavic language speaker, that's fair, but it's mostly a testament to how complex all Slavic languages are. It's like we decided to make it absolutely sure that any foreigner who decided to learn them would be in a world of pain. Declensions? Check. Grammatical gender? Sure, and adjectives and verbs also have it for good measure, not just nouns; and for verbs, it also interacts with tense and number.

And let's not forget about our phonology, with 5-consonant clusters, palatalized labials, utterly unpredictable stress, complex mutations of both consonants and vowels when adding suffixes etc.

By the way, the nearly universal ethnic designation for Germans in Slavic languages - some variation of "nemci" - literally means "mutes".