Sample: I tell it in German to send a message to Peter to meet me in Starbucks.
Now how you pronounce “Starbucks” in German? Of course you speak it the proper English way. Not a chance that Siri will recognize it. Try other words, like “iPad”.
Quite a shame. The German Siri doesn’t know the word iPad.
Same issue if you try to mention names of Thai Cities. While Bangkok works, Pattaya or Rayong doesn’t. Most other names aren’t recognized as well.

So the engineers will have to make some improvements to have non-english Siri understand certain popular english names.

But for a beta it is nevertheless pretty good and very helpful.