For young puppy biters... if they are not getting your language... use their language... act like their birthmom and growl at them. Experiment till you find the type of growl that makes them stop in their tracks... and then teach them English, or whatever language you prefer... works especially well with pups who were not allowed to stay with their birthmoms till 12 weeks... and others too!
Change pitch of growl (high to low) and change volume until the expected response is achieved.