To your 2nd question you could potentially use "anwenden", "verwenden" or "benutzen". Even so you may also use another sentence in German alongside the traces of "Um eine Sprache zu lernen muss person sie sprechen" which would seem fewer scientific. Regardless of the validity of Nohl's edition, an editorial peculiarity https://softwareentwicklung87531.dreamyblogs.com/29155168/softwareentwicklung-for-dummies