My hypercritical-of-grammar former boss used to speak in ebonics and would say things like, we should all say xyz instead of 123 because it would be 'benefitical' to us.

She'd also tell callers her assistant was busy and so "I'll have her to call you back" because "Sheila is conversating with someone else right now"

Okay, so I am not the most perfect presenter but it is an important part of my job and I get and give feedback frequently. Just because I am not perfect doesn't mean I can't recognize challenges in others speaking styles (and vice versa). I have found it helpful to get feedback, whatever the source, and others have told me they appreciate my views. Just take the feedback for what it's worth and work on it.

You might consider videotaping a presentation as that will give you a good sense of your speaking style and nervous habits. You can also do speaking coaching or training - see if your company wil pay for that.

I have an employee who says "like" all the time and it drives me bat-shit crazy. She is otherwise a very strong performer. I have mentioned it to her on several occasions, including as part of her evaluation, and tried to be supportive and constructive. I told her I have great respect for her work, and want others to also respect her work, but the overuse of "like" makes her sound immature and unprofessional. She's in her mid 30s so it isn't as though she just rolled off a college campus. I can tell she thinks I'm crazy but I don't think she has any idea of how often she says it.

Anyhow, I know it's hard, but my suggestion would be to take the feedback and act on it. I know it's tough to hear from someone who commits her own blunders but try to see it as an opportunity to improve an already good profile, and for extra credit, maybe even thank the supervisor for the constructive criticism so she knows you're taking it to heart.

Hopefully, she also takes the time to tell you when you do things right. Good luck!