An example of SSML markup and how it's read back by the Google Assistant.

AoG-SSML-example.html

<speak>
  Here are <say-as interpret-as="characters">SSML</say-as> samples.
  I can pause <break time="3s"/>.
  I can play a sound
  <audio src="https://www.example.com/MY_MP3_FILE.mp3">
    didn't get your MP3 audio file
  </audio>.
  I can speak in cardinals. Your number is 
  <say-as interpret-as="cardinal">
    10
  </say-as>.
  Or I can speak in ordinals. You are 
  <say-as interpret-as="ordinal">
    10
  </say-as> in line.
  Or I can even speak in digits. The digits for ten are
  <say-as interpret-as="characters">
    10
  </say-as>.
  I can also substitute phrases, like the 
  <sub alias="World Wide Web Consortium">
    W3C
  </sub>.
  Finally, I can speak a paragraph with two sentences.
  <p>
    <s>This is sentence one.</s>
    <s>This is sentence two.</s>
  </p>
</speak>