diff -u b/core/includes/common.inc b/core/includes/common.inc
--- b/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -3671,7 +3671,7 @@
  * outermost renderable array (also known as an "element") is processed using
  * the following steps:
  *   - If this element has already been printed (#printed = TRUE) or the user
- *     does not have access to it (#access = FALSE) then an empty string is
+ *     does not have access to it (#access = FALSE), then an empty string is
  *     returned.
  *   - If this element has #cache defined then the cached markup for this
  *     element will be returned if it exists in drupal_render()'s cache. To use
@@ -3715,7 +3715,7 @@
  *     - If this element does not have a defined #theme, or the defined #theme
  *       hook is not implemented, or #render_children is set, then
  *       drupal_render() is called recursively on each of the child elements of
- *       this element and the result of each is concatenated onto #children.
+ *       this element, and the result of each is concatenated onto #children.
  *       This is skipped if #children is not empty at this point.
  *     - Once #children has been rendered for this element, if #theme is not
  *       implemented and #markup is set for this element, #markup will be
@@ -3723,7 +3723,7 @@
  *   - If this element has #states defined then JavaScript state information is
  *     added to this element's #attached attribute by drupal_process_states().
  *   - If this element has #attached defined then any required libraries,
- *     JavaScript, CSS or other custom data are added to the current page by
+ *     JavaScript, CSS, or other custom data are added to the current page by
  *     drupal_process_attached().
  *   - If this element has an array of #theme_wrappers defined and
  *     #render_children is not set, #children is then re-rendered by passing the