There are two ways to display a node in a Drupal site - its full view, and its teaser view.  The teaser view, which is used on pages where multiple nodes are shown, usually has a truncated version of the main body text.  The system determines this automatically by taking the entire first paragraph of the body, if it contains fewer than 600 characters, or by taking the first 600 characters if the first paragraph is too long, or if the body does not contain identifiable paragraphs.

If you wish to override the way the system determines the teaser part of the body, you may select the "Edit summary" link to open up a separate editor window, and type exactly what you want to be used for the teaser.  Generally, you will not need to use this feature.

A spell-check feature is available in the WYSIWYG editor, but is disabled by default.  There are two spell-check icons in the top bar of the editor window - both showing "ABC" and a checkmark.  Use the one on the left to check the entire body of your post one time.  Or to have the editor spell-check as you type, click the icon on the right, then select "Enable SCAYT" from the dropdown menu.