As an additional anec-datapoint here, I've noticed it's a relatively common habit amongst native english speakers who have some degree of dyslexia. I've asked a

As an additional anec-datapoint here, I've noticed it's a relatively common habit amongst native english speakers who have some degree of dyslexia. I've asked about it once or twice, and the most consistent answer is something like 'I don't even notice I'm doing it; when I finish a word I insert a space, then think about the punctuation and add it on...' This is not to suggest that this structure indicates dyslexia of course, the rest of this thread has plenty of other good reasons for non-native english speakers and otherwise.