Werewolves that are stuck in one single shape are called yennorks. There can be two kinds of yennorks: either they are entirely in human-shape, even during the full moon. Or they are in wolf-shape all the time.
Nevertheless, this doesn't make it easier for the yennorks. They are not accepted by real wolves, as they can still sniff out the werewolf in them, even if they are in wolf-shape.
Although a yennork stuck in human shape might pass as a human, it would still not be advisable to marry a human, as the werewolf genes might still break out in their offspring. Some speculate that some monstrous, violent wolfmen, and some wolves that are exceptionally cunning and cruel, are descendants of yennorks married into human families or wolf clans, respectively.
Furthermore, yennorks are not really accepted by the werewolves themselves, at least not by the traditionalists among them. They see their inability to shape-shift as an abomination of nature. To keep the werewolf-blood pure, some parents would even kill their babies if they were born yennorks.