[LouisSayers]

It's hard to say unless you had a recording of yourself in a conversation to listen to / watch why exactly you're getting this response.

As others have mentioned: tone, pacing, modulation, content ... these could all contribute, but I don't think you'd be able to know unless you really analysed a video or audio recording with someone.

Here's a few things that may help:

  1) Get a voice coach and do a few lessons
  2) Join an acting class
  3) Take a clip from a movie and re-enact it. Record yourself and play it back to see the difference, you might pick up a few things.

Also, as others have mentioned it might be worth not paying as much emphasis on speaking, but focus more on listening, reflecting and asking questions. People like others that are intrigued by and like them!