The types of words that might get one's speech stereotyped as "lazy" or "disfluent" or "uneducated" or whatever else if used excessively or in too formal a setting, but which in truth are vital for fluency and listening comprehension.

I dunno, this is just an impression because I don't interact much with the broader conlang community, but I feel like these words often end up being sort of overlooked by many conlangers. I certainly overlooked them for a long time myself. But to me these words make a language feel that much more alive, you know, that different people talk in different ways with different registers.

Do any of you have any interesting thoughts or experiences with these types of words? How are they handled in your own conlangs?