diff --git a/src/ThemeFunctionDeprecationAnalyzer.php b/src/ThemeFunctionDeprecationAnalyzer.php
index 9aa9681..4ad658c 100644
--- a/src/ThemeFunctionDeprecationAnalyzer.php
+++ b/src/ThemeFunctionDeprecationAnalyzer.php
@@ -41,7 +41,7 @@ final class ThemeFunctionDeprecationAnalyzer {
   }
 
   /**
-   * Analyzes theme functions in the extension.
+   * Analyzes theme functions in an extension.
    *
    * @param \Drupal\Core\Extension\Extension $extension
    *   The extension to be analyzed.
@@ -57,8 +57,9 @@ final class ThemeFunctionDeprecationAnalyzer {
     // If a theme is being analyzed, theme function overrides need to be
     // analyzed.
     if ($extension->getType() === 'theme') {
-      // Create new instance of theme registry to ensure that we have most recent
-      // data without having to make changes to the production theme registry.
+      // Create new instance of theme registry to ensure that we have the most
+      // recent data without having to make changes to the production theme
+      // registry.
       $theme_registry = new Registry($this->container->get('app.root'), new NullBackend('null'), $this->container->get('lock'), $this->container->get('module_handler'), $this->container->get('theme_handler'), $this->container->get('theme.initialization'), $extension->getName());
       $theme_registry->setThemeManager($this->container->get('theme.manager'));
       $theme_hooks = $theme_registry->get();
@@ -69,9 +70,9 @@ final class ThemeFunctionDeprecationAnalyzer {
           $function = new \ReflectionFunction($extension->getName() . '_' . $machine_name);
           $file = $function->getFileName();
           $line = $function->getStartLine();
-          $deprecation_messages[$extension->getName() . '_' . $machine_name] = new DeprecationMessage(sprintf('The theme is overriding "%s" theme function. Theme functions are deprecated. For more info, see https://www.drupal.org/node/2575445.', $machine_name), $file, $line);
+          $deprecation_messages[$extension->getName() . '_' . $machine_name] = new DeprecationMessage(sprintf('The theme is overriding the "%s" theme function. Theme functions are deprecated. For more info, see https://www.drupal.org/node/2575445.', $machine_name), $file, $line);
         } catch (\ReflectionException $e) {
-          // This should never happen because drupal_find_theme_functions
+          // This should never happen because drupal_find_theme_functions()
           // ensures that the function exists.
         }
       }
@@ -81,11 +82,11 @@ final class ThemeFunctionDeprecationAnalyzer {
   }
 
   /**
-   * Analyzes function for usages of theme functions.
+   * Analyzes function for definition of theme functions.
    *
    * This doesn't recognize functions in all edge cases. For example, theme
-   * functions could be generated dynamically in number of different ways.=
-   * However, this will be useful in most basic use cases.
+   * functions could be generated dynamically in a number of different ways.
+   * However, this will be useful in most use cases.
    *
    * @param $function
    *   The function to be analyzed.
@@ -95,10 +96,12 @@ final class ThemeFunctionDeprecationAnalyzer {
    * @return \Drupal\upgrade_status\DeprecationMessage[]
    */
   private function analyzeFunction(string $function, Extension $extension): array {
+    $deprecation_messages = [];
+
     try {
       $function_reflection = new \ReflectionFunction($function);
     } catch (\ReflectionException $e) {
-      // It is expected that the functions don't exist.
+      // Not all extensions implement theme hooks.
       return [];
     }
 
@@ -106,26 +109,26 @@ final class ThemeFunctionDeprecationAnalyzer {
     try {
       $ast = $parser->parse(file_get_contents($function_reflection->getFileName()));
     } catch (Error $error) {
-      // Function cannot be evaluated because of a syntax error.
-      return [];
+      // The function cannot be evaluated because of a syntax error.
+      $deprecation_messages[] = new DeprecationMessage(sprintf('Parse error while processing the %s hook implementation.', $theme_function), $function_reflection->getFileName(), $node->getStartLine());
     }
 
     if (!is_iterable($ast)) {
       return [];
     }
     $finder = new NodeFinder();
-    // Find node for the function that is being analyzed.
+    // Find the node for the function that is being analyzed.
     $function_node = $finder->findFirst($ast, function (Node $node) use ($function) {
       return ($node instanceof Function_ && isset($node->name) && $node->name->name === $function);
     });
 
     if (!$function_node) {
-      // This should never happen because the file has been loaded the based on
-      // the existence of the function.
+      // This should never happen because the file has been loaded based on the
+      // existence of the function.
       return [];
     }
 
-    // Find theme functions that has been defined using array syntax.
+    // Find theme functions that have been defined using the array syntax.
     // @code
     // function hook_theme() {
     //   return [
@@ -136,14 +139,13 @@ final class ThemeFunctionDeprecationAnalyzer {
     $theme_function_nodes = $finder->find([$function_node], function(Node $node) {
       return ($node instanceof ArrayItem && $node->key instanceof String_ && $node->key->value === 'function');
     });
-    $deprecation_messages = [];
     foreach ($theme_function_nodes as $node) {
       $theme_function = $node->value instanceof String_ ? sprintf('"%s"', $node->value->value) : 'an unknown';
       $deprecation_messages[] = new DeprecationMessage(sprintf('The %s is defining %s theme function. Theme functions are deprecated. For more info, see https://www.drupal.org/node/2575445.', $extension->getType(), $theme_function), $function_reflection->getFileName(), $node->getStartLine());
     }
 
-    // Find theme functions that are being added to existing array using array
-    // square bracket syntax.
+    // Find theme functions that are being added to an existing array using 
+    // the array square bracket syntax.
     // @code
     // function hook_theme_registry_alter(&$theme_registry) {
     //   $theme_registry['theme_hook']['function'] = 'another_theme_function';