YOU SAID:

Oh should I say hi in German or in English. Well she doesn't know I speak German too yet I'm gonna surprise her.

INTO JAPANESE

ああ、私はドイツ語または英語でこんにちはと言う必要があります。彼女は私がまだドイツ語を話せないことを知らないが、私は彼女を驚かせる。

BACK INTO ENGLISH

Oh, I have to say hello in German or English. She doesn't know that I can't speak German yet, but I surprise her.

INTO JAPANESE

ああ、私はドイツ語または英語で挨拶しなければなりません。彼女は私がまだドイツ語を話せないことを知りませんが、私は彼女を驚かせます。

BACK INTO ENGLISH

Oh, I have to say hello in German or English. She doesn't know that I can't speak German yet, but I surprise her.