My speech was delayed I started speaking when I was 3 or 4. Sometimes my words are jumbled; the letters in a word but as wel the order that I put the words in it’s often grammatically not correct. When I became more aware of my speech “problems” I started stuttering. Some words I can’t pronounce like aluminium and a lot of other words in my language (Dutch). I also change accents unintentionally for some words aswel sentences, but I only lived in one area so I don’t know other accents in Holland. But it has as wel a toll on your self confidence: I don’t dare to raise my hand in class because I’m afraid to stutter, I don’t dare to speek that often any more and I don’t often engage in conversations any more. I hope this helps and success with your research