A question I often get asked is “When do I use wissen and when kennen?”
A quick look in the dictionary tells you both mean ‘to know’. So, are the interchangeable? Sadly, no!
You use ‘kennen’ when you know a person or a place or are familiar with things
Ich kenne den Mann. I know that man.
Ich kenne München gut. I know Munich well.
Ich kenne den Film. I know (of) that film.
All those sentences have a direct object – the item/ person you know or are familiar with.
You use ‘wissen’ when you know a fact.
Ich weiß, wo du wohnst. I know where you live.
Weißt du, wie spät es ist? Do you know what time it is?
Wir wissen, wann das Konzert anfängt. We know when the concert starts.
My little picture above (which you could print and turn into a bookmark if you wish) may give you just the nudge you need:
Ich kenne Ken. I know Ken,and Ken is in kennen.
Das muss man wissen. You need to know that, or, you need wisdom to know that you need to use wissen
Is this information useful? Please let me know and tell me if you’d like to see any other grammar explained.