Compound nouns in Czech grammar are formed by combining two or more words into one new word. This new word usually describes a unique concept, object, or idea. In Czech, compound nouns are very common and often used in everyday conversations and written texts. They can be made up of different parts of speech, such as nouns, adjectives, or verbs, and are often formed by adding a prefix or suffix to an existing word. By understanding how compound nouns are formed, you can easily expand your vocabulary and improve your communication skills in Czech.