Think of it this way: someone says to you that they're looking for a cookbook with a specific recipe. You can then say, "I know a book!", implying that you know a book which has that recipe in it, before telling them what the book is. I hope this makes sense.
Leider, nein. According to DeepL translator, the correct translation for "I know German" is "Ich kann Deutsch."
Kennen is used for direct, identifiable knowledge. For example, "I know Anna", "I know that restaurant", "I know that book". Wissen is for general knowledge. "I dont know about that", "I know how to speak English", etc.
i know one too his name is fred he’s very nice he likes wearing a red dust jacket
- denken = to think
- wissen = to know (a fact), i.e. "I know you are happy"
- kennen = to know (a person or object), i.e. "i know you"
The thing is there's a distinction which should be made here by the duoLingo team between British and American English.
The idiomatically correct American English expression would be "to be familiar with".
In American English, "to know" would mean personal familiarity, as in "I know my sister, and [she wouldn't like her toast burned]."