"I do not know the route."
Translation:Ik ken de route niet.
I don't know the stated rule (and even if I did then there would be toooo many exceptions to put to memory). But I have observed that whenever there is an object (in this sentence, route) following the verb (ken), the Dutch like to keep the two together (ken de route). This leaves auxiliary modifiers to be placed after the object, in this case the adverb niet.
English-speakers (as a rule, but not always) keep the negating adverb with the verb: "do not know" or "know not".
I take it with humor. I might already be putting on my coat to go somewhere, when at the end of a long sentence there comes the niet, and then I must take it off.
Weten is used when it's about knowledge
- Ik weet het antwoord = I know the answer
- Ik weet veel van taal = I know much about language
- Ik weet het niet = I don't know
- Ik weet waar Abraham de mosterd haalt = I know where Abraham gets the mustard
- Ik weet waar haar huis staat = I know where her house is situated/stands
- Ik weet niks over die straat = I know nothing about that street
Kennen is used for knowing people/places + see Simius' post
- Ik ken hem goed = I know him well
- Ik ken haar huis goed = I know her house well
- Ik ken die straat niet = I don't know that street
If you understand the difference between the last examples of both lists, then you know the difference between weten and kennen. :)
"Kennen" is not just for people or places, it can be used for any object or even abstract concepts:
- Ik ken dit verhaal = I know this story
- Ik ken die broek niet = I don't know those pants
I think it's easiest to keep in mind that "kennen" means to be acquainted with or to be familiar with. It means that you know about something, whereas "weten" implies understanding. Looking back at Susande's first example, you could also say:
- Ik ken het antwoord = I am familiar with the answer
This is different from "Ik weet het antwoord". It implies that the speaker did not come up with the answer: it's somebody else's answer and the speaker knows what it is. For example, it might be the answer to a riddle that you've heard before.
Yes, there's a difference.
If you say 'ik ken de route niet' it means that you are unfamiliar with the route, but to say that you don't have knowledge of the route (of that particular route, of an alternative route to the one you know), you'd say 'ik weet van geen enkele andere route'.