From my own experiences, it definitely depends on the situation/person. If I am at work, I get very annoyed when my boss or coworkers say words for me because I believe they should respect me enough to wait the extra 10 seconds until I can get it out. I have to listen to them all day so they should listen to me. But if it’s my husband, close friend, or immediate family I don’t mind when they help out because I know it’s coming from a place of love not impatience. Strangers don’t often try to fill in words for me so not sure how I would feel about that. They usually just stare/glare or awkwardly chuckle.