So the waiter is always incorrectly assuming that you've finished your sentence when you are just in the middle of a block. Instead of giving up, would you be able to copy [this singer](https://www.youtube.com/watch?v=eYuu1D8p8uU)'s secondary behaviors? The reason I'm bringing up that singer is, despite her stutter, her non-verbal mannerisms clearly mark the beginning of her speech, and middle pauses/blocks, and the end of her speech. So when she is in the middle of a block, everyone knows she is not finished. Eye contact when she begins speaking or when she is done speaking. But closed eyes during blocks, a hand on chest, except for blocks followed by "um".