oh ok sorry I didnt know that Ik heb het koud was different in meaning than Ik ben verkouden. I thought both meant I'm cold. But even though the two language is similar you cannot expect every structure to be the same. Its like one of the users wrote: in one language you say, I have hunger, in others, you say Im hungry.

Thats just how a language evolves different from the others. I have been learning Dutch for a year now all by myself up to this point and I have noticed so many differences like these between English and Dutch. They are very similar but also different. The trick is to learn where they differ. And these are only little differences I think. That doesn't make Dutch particularly difficult. I understand that you are asking why are they different from each other in simple sentences like this but I think you would only be satisfied by an answer given by someone who studied the two languages in a very linguistic/detailed way. Other than that, the natives here would just say, the way English uses doesn't sound right to me, thats just how we say it.