<div contenteditable>
<p>This is a test line that is very very very very very very very very long.</p>
<p>And this is another test line.</p>
</div>

Using Voiceover on Mac, focus the first word.
Press Option-right and observe the whole line is being read instead of the first word.
Press down and observe that the whole paragraph is being read instead of the current line.

This only happens for the first word of every paragraph.