kennen vs. wissen
"Kennen" is not the same as "wissen" and it can be very confusing trying to tell the two apart.
Here you will learn what "kennen" means, what "wissen" means, and finally how to tell the difference.
There are example sentences, too, and I highly recommend you grab your German notebook and write them down so you can refer back to them later.
Ich kenne... is for things you can get to know. You might not have always known your German friend Marius, however you got to know him once, which means you can now say "Ich kenne Marius."
If you've been to Berlin and have seen the sites and have enjoyed the restaurants and have an idea of what it's like, then you can say "Ich kenne Berlin."
If you have seen the movie "Das Leben der Anderen," then you can say "Ja, den Film kenne ich!"
But if you, like me, haven't yet been to Bremen, you don't know Marius and you also haven't seen the latest German blockbuster, you then say "Nein, ich kenne _______ nicht."
You use "wissen" when you learn a fact about a thing, for example, "Ich weiß, dass Albert Einstein sehr intelligent war!"
When you tell your little cousin, your kid or your step-kid that you know they like ice cream, because s/he has told you a million gazillion times, then you say "Ich weiß! Du magst Eis."
If you know how to make that ice cream, then you say "Ich weiß, wie man Eis macht."
kennen vs. wissen
You can 'wissen' that Brazil is a large country in South America. But you can only 'kennen' Brazil if you've been there.
Ich kenne Brazilien nicht. Ich war noch nie da.
Ich weiß aber, dass Brazilien ein großes Land in Südamerika ist!
If you've met German actor Franka Potente, you can say that you 'kennen' her.
Ich kenne Franka Potente.
Moreover, when you met her, she told you about how hard she works, then you can 'wissen' something about her.
Ich weiß, dass sie hart arbeitet. Das hat sie mir gesagt!