The K sound and the G sound are produced the same, except that G is voiced, while K is not. Thus, when those two sounds are placed back-to-back in a word or consecutive words, it is slightly awkward to enunciate.
I have a good name. Mark Green. Simple enough, except that it is difficult to say plainly in a hurry, because a space has to be put between the K and the G and it sounds a little like you are gagging.