- speak vehemently
- utter vehemently
When should one use speak and when utter?
It's useful to think of it this way: To utter means to make a sound; to speak means to make an intelligible sound.
I'm being deliberately simplistic here just to underscore the main difference. The truth is a little more complicated.
So utter also means to "say aloud"; but speak has a more precise definition. (And one wonders why "aloud" is needed at all in the above entry.)
Not that this is always the case. Every word you speak aloud is an utterance, but not every utterance is of informational value.