With me it's a confidence issue. Sometimes when i put no pressure on myself to speak, i am fluent. When i put pressure on myself, i stammer more. If speaking is considered as an analog to sprinting, if i take position to sprint and i am waiting for the count down to start so that i can start to sprint, i get paralysed. Instead of taking position to sprint preemptively, if i am at ease and when it's time to start sprinting, if i start sprinting calmly, i don't get paralysed as much. So, it’s something like i shouldn’t preemptively keep myself ready to speak. When its the right time, I should let my speech flow with as less force as possible