You are right that German is handled differently when spellchecking. In this regard, attached is a simple application demonstrating how you can implement spellchecking in German in RadRichTextBox. The dictionary is taken from this forum post
and the nouns in it start with uppercase letter, meaning that not only would nouns be checked properly, but if they are written with lowercase letter, they will be marked as an error.
Let me know if any additional questions arise.
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