First, realise that everyone has sympathy with the stutterer and wants his conversation to be trouble free. Identify those words or strings of words that typically cause you to stutter and find safer words that confer the same meaning. The stutter will undoubtedly worsen when you are stressed or feel under pressure. Therefore try to stand by those people with whom you feel comfortable and don't speak until you feel confident.
Where you have been asked a question so that you have to speak, take your time. Use pauses to prepare your words. It is hard to suffer from a stutter but speaking with care and taking your time will help. Smile, where possible, because your listeners will be tense if you are stuttering. If they smile back at you, this positivity will increase your confidence and enable you to finish your sentences more successfully.
It may not be easy to stop stuttering during social situations but there are a few things you can try. Experts currently believe stress and stuttering are related. The more a person stutters, the more anxious they become. Then, the more anxious a person becomes, the more they stutter.
You can try reducing your anxiety in social situations by slowing your speech and regulating your breathing. If your anxiety or fear is only about your stuttering and not so much about social anxiety, speech therapy or a self-help group might prove to be a successful treatment option for you.