How to teach your dog to stop pulling?
Yes,tessiyoko is right.If the dog starts to pull, stop walking & stand still & then repeat when required. Soon the dog will associate standing sill with pulling & work out "no pull, yes walk & vice versa.Also you could the dog a treat immediately once the dog has stopped pulling. It's called positive reinforcement. Worth googling.
To stop pulling on the leash? My dog used to do this years ago. What you want to do is just stop walking and make them heal. You want to train the dog to sit. Also, pulling back a little bit could help as well.