Of course a German professor would say that. (-: I've taken years of both languages in high school and college, and I'd have to disagree with him. An example of the difference in difficulty is that when you learn German coming from an English background there are only four more letters to learn (ä, ö, ü and ß), whereas there are 214 Mandarin radicals to memorize. And these radicals aren't even the entire "alphabet", they're just the basis that all characters expand upon.
Also, Mandarin is a tonal language, along with having vastly different grammar than Germanic languages. While English has plenty of influence from Romance languages, most of it is strictly vocabulary; English, at its core, is a Germanic language. Thus it'd be rather hard to prove that German is more difficult for an English speaker to learn than Chinese. However, I would love to hear his arguments to the contrary, or anybody else's for that matter!
I know almost no German, but I learned French to fluency and know spoken Mandarin somewhat well.
I think that talking about the relative difficulty of a language as a whole is not really workable. There are different aspects which order differently.
For example, if you already speak English then you'll find German vocabulary far easier to learn. There will be a lot of shared or similar words that you can build on. In Mandarin, there are almost no common words, so you basically have to start from scratch.
On the other hand, Mandarin grammar is pretty simple. No conjugations, no genders, just slightly different word order from what you're used to. If you know how to say "I eat noodles" and you know how to say "yesterday" then you know how to say "I ate noodles yesterday". We spent a long time learning how to conjugate the various past tenses in French class, and I believe German is similar.
I think there's no contest when it comes to reading and writing. Learning to read and write Mandarin is almost like learning a whole separate language from the spoken version.
I think the easy grammar helps give Mandarin a big advantage, especially if you're learning it for casual conversations. But that advantage is greatly reversed in other areas. Much will depend on what the individual language learner finds easy and hard to learn.
> On the other hand, Mandarin grammar is pretty simple. No conjugations, no genders, just slightly different word order from what you're used to
That's interesting to me as this week I stumbled into Afrikaans, which likewise lacks genders and conjugations and only apepars to have two tenses ( present and perfect ).
Which makes me wonder why other languages have evolved to such levels of complexity, since it seems entirely possible to conduct the affairs of a state without have a distinction between 'I eat' and 'he eats'.
Without knowing how closely related the learner's own language is, it's meaningless. For example, a Dutch speaker would likely find German easier to learn than Chinese. On the other hand, (Mandarin) Chinese is easier for a Cantonese speaker to learn than German.