It truly is and sometimes there's not much that you can do. But don't let that stop you from trying. Here's a few tips that had sometimes helped me when I am speaking in public: 1. If you feel that a block is coming, then try to slow down and stretch out the word. If that does not work out then use a synonym in its place. Though that might not be possible when you're giving a technical speech. 2. Use over articulation. Sometimes that makes it easier to get the word out. 3. Try to speak in a rhythm. 4. Make greater use of inflections. 5. Don't just speak with words. Use body language. Hand gestures, eye contact, expressions, etc. Make the speech livelier. If you are speaking on a podium then try to move around. Not too much, that could be distracting to the audience. 6. Use props if you can. For example if you are teaching, you can write some stuff on the board and that way even if you have difficulty saying it, your students will still understand the topic. 7. Try to add some humour to your speech. 8. And most importantly, practice the speech multiple times before speaking in front of a public. Even those who don't stutter often have difficulty in giving good public speeches. Practice immensely helps in this regard. Practice your speech in front of your friends or family and ask them for feedback. 9. Also if you want you can announce to the audience beforehand that you stutter. You will probably be able to speak more freely if you do that.