Rule of thumb: 'Kennen' is used for persons and for things you can learn or know of by experience.
- 'Ik ken de directeur': I know the director.
- 'Ik ken de les': I know the lesson (after having learned it).
'Ik ken het museum': I know the museum (for instance because I've been there).
'Ik weet waar het museum is': I know where the museum is.
- 'Ik weet welke les ik moet leren': I know what lesson I have to learn.
- 'Ik weet wie de directeur is': I know who the director is.
Shot in the dark here, if you're familiar with spanish or french I think the difference between "ken" and "weet" is the same as "conocer" vs "saber" in spanish or "connaitre" vs "savoir" in French. I know Bob, he works with me (use: ken/conocer/connaitre) I know how to cook (use: weet/saber/savoir)
MarcinTust, it does not matter how you learned where the museum is -- whether from a book or from personally going there. Once the location of the museum is a fact or abstract piece of knowledge, then you use weten.
I know the museum well -> kennen
I know where the museum is -> weten
I know that she knows him -> first weten, then kennen
"Ik ken Beyoncé, maar ik weet niets van haar"
"I know (am familiar with) Beyoncé but I know nothing about her"
To my knowledge using the above example sentence we have:
1) Ik ken Beyoncé
"Kennen" is used to describe familiarity with an object so you can know a celebrity /a book / a movie etc... (even if you have no knowledge ABOUT the object). So in the example above I can know who Beyoncé is i.e be familiar with Beyoncé cause I've seen her on TV or heard her on the radio (I do not have to have knowledge about her).
2) "... maar ik weet niets van haar"
"Weten" is used when you have knowledge ABOUT a piece of information such as a characteristic of an object / the answer to a question etc... So in the example above it could mean I do not know Beyoncé intimately in otherwords I have no information about her. I do not know what her likes / dislikes are, how big her feet are etc...
In summary "Kennen" is being aware of something due to having contact with it previously (even if you have no knowledge ABOUT the thing) and "Weten" is having knowledge about a piece of information so is generally used in reference to an idea or a specific piece information about the object.
Well at least that's my understanding
Buiu, Is your sentence "Ik ken Beyoncé, maar ik weet haar niet" your own creation, or did you get it from a native speaker? I ask because it doesn't look right to me.
If your sentence were something like "I know Beyoncé, but I don't know much about her" -- then yes, "weet" the second time in the Dutch translation. But I don't think you can "weet" a person, only things, facts, etc. about them.
Apologies you're right "Weten" only refers knowledge about a piece of information so I've changed my original post accordingly.
Also some my find this link useful for getting further examples of when "Weten" and "Kennen" should be used
This is how I understand it, but some of what I say might be wrong:
'Of' is used when there is uncertainty and can be translated by the English word 'whether'. 'Als', on the other hand, can mean 'when', indicating a level of certainty. This gets confusing when translating to English because in both of these cases English can use the word 'if'. Here are some examples:
Lili vraagt of jullie morgen ook naar zee gaan. = Lili asks whether (if) you are also going to the sea tomorrow.
Lisanne lacht altijd als ze Vincent ziet. = Lisanne always laughs when (if) she sees Vincent.
The easiest way to go about it is to think of 'als' as 'when' and 'of' as 'whether' for most cases when translating Dutch into English, but you should always keep in mind that they can both be rendered by 'if' in English, which is important to know when translating from English into Dutch.
Here is a useful page, but may be difficult because it is in Dutch. The examples (some of which I used) should be helpful though :)
Indien is generally of higher style (more formal, less colloquial) but can be used to emphasise the hypothetical nature of an issue. Als may be seen and used colloquially/informally more frequently.
You should use 'of' in this sentence.
When you are trying to find the proper Dutch word to (roughly) render the English word 'if', consider the context of the particular use of the English word 'if'. Is it indicating the English equivalent of whether?
The Dutch 'of' can play a role as both a co-ordinating conjunction (for example: when used to render English 'or') and a subordinate conjunction (for example: when used in place of English 'whether').
"Ik weet niet of [whether] hij thuis is." -- I don't know whether/if he is home (or not).
"Wil je sap of [or] water?" -- Do you want juice or water?
The word "of" can be a conjunction meaning "or". Then, just as you say, it is a coordinating conjunction. However, the word "of" can also be a subordinating conjunction meaning "if/whether". That is its role in the DL sentence here.
How can you tell whether the "of" in a Dutch sentence means "or" or "whether"? Well, one way to tell is that if there is inversion, then it means "whether"!