hey there! my wife is german so maybe i can help but i realize this maybe a lil late.
in german they say sittich & groß sittich. groß sittich generally refers to the larger parakeets. groß in german means big. however a cockatoo or a parrot are not considered under sittich or groß sittich.
for example, we call ziegensittich or in english kakariki a groß sittich. however, a budgerigar is known as a wellensittich and it is not considered to be a groß sittich. i hope this helps answer your question. i dont think there is an exact translation to english for groß sittich. no offense to native born english speakers, but as a person who speaks a few languages, english is known to have a smaller vocabulary as compared to german or russian for example. again no offense intended. if you do find an exact translation i´d be happy to know.
have a nice day
