One of the most common -- and important -- elements in any text document is the paragraph.
Mark the beginning of paragraphs in your text using the <P> tag.
I recommend that you close each paragraph with the </P> tag. Strictly speaking, this is not required, but it can help to avoid confusion.
Here's an example:
<P> Blah blah blah blah blah, blah blah blah blah. Blah blah blah blah, blah and blah. Blah blah blah blah, blah blah blah blah; blah blah blah blah, blah blah, blah blah blah. Blah blah: blah, blah, blah, blah, and blah. Blah blah! </P>
The paragraph is a block-level element.