The W3 reference links provided below may be helpful for additional context and examples.
What tts elements are supported? Applicable for both dynamic and static TTS
Do not use <speak> element as it is already hardcoded.
<break>
An empty element that controls pausing or other prosodic boundaries between words. Using <break> between any pair of tokens is optional. If this element is not present between words, the break is automatically determined based on the linguistic context.
The following example shows how to use the <break> element to pause between steps:
mu
<p>,<s>
Sentence and paragraph elements.
To learn more about the p and s elements, see the W3 specification.
Example
<p><s>This is sentence one.</s><s>This is sentence two.</s></p>