diff --git a/lib/ddl/oracle_sql_generator.php b/lib/ddl/oracle_sql_generator.php
index 996b9b69c55..48ba6bd46f2 100644
--- a/lib/ddl/oracle_sql_generator.php
+++ b/lib/ddl/oracle_sql_generator.php
@@ -30,7 +30,7 @@ require_once($CFG->libdir.'/ddl/sql_generator.php');
 
 /// This class generate SQL code to be used against Oracle
 /// It extends XMLDBgenerator so everything can be
-/// overriden as needed to generate correct SQL.
+/// overridden as needed to generate correct SQL.
 
 class oracle_sql_generator extends sql_generator {
 
@@ -89,7 +89,7 @@ class oracle_sql_generator extends sql_generator {
 
     /**
      * Given one xmldb_table, returns it's correct name, depending of all the parametrization
-     * Overriden to allow change of names in temp tables
+     * Overridden to allow change of names in temp tables
      *
      * @param xmldb_table table whose name we want
      * @param boolean to specify if the name must be quoted (if reserved word, only!)
@@ -134,7 +134,7 @@ class oracle_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one XMLDB Type, lenght and decimals, returns the DB proper SQL type
+     * Given one XMLDB Type, length and decimals, returns the DB proper SQL type
      */
     public function getTypeSQL($xmldb_type, $xmldb_length=null, $xmldb_decimals=null) {
 
@@ -302,7 +302,7 @@ class oracle_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to alter the field in the table
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to alter the field in the table
      * Oracle has some severe limits:
      *     - clob and blob fields doesn't allow type to be specified
      *     - error is dropped if the null/not null clause is specified and hasn't changed
@@ -467,7 +467,7 @@ class oracle_sql_generator extends sql_generator {
             }
         }
 
-    /// If arriving here, something is not being skiped (type, notnull, default), calculate the standar AlterFieldSQL
+    /// If arriving here, something is not being skipped (type, notnull, default), calculate the standard AlterFieldSQL
         if (!$skip_type_clause || !$skip_notnull_clause || !$skip_default_clause) {
             $results = array_merge($results, parent::getAlterFieldSQL($xmldb_table, $xmldb_field, $skip_type_clause, $skip_default_clause, $skip_notnull_clause));
             return $results;
@@ -478,7 +478,7 @@ class oracle_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to drop its enum
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to drop its enum
      * (usually invoked from getModifyEnumSQL()
      *
      * TODO: Moodle 2.1 - drop in Moodle 2.1
@@ -497,7 +497,7 @@ class oracle_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to create its default
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to create its default
      * (usually invoked from getModifyDefaultSQL()
      */
     public function getCreateDefaultSQL($xmldb_table, $xmldb_field) {
@@ -517,7 +517,7 @@ class oracle_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table returns one array with all the check constrainsts
+     * Given one xmldb_table returns one array with all the check constraints
      * in the table (fetched from DB)
      * Optionally the function allows one xmldb_field to be specified in
      * order to return only the check constraints belonging to one field.
@@ -549,7 +549,7 @@ class oracle_sql_generator extends sql_generator {
             $filter = $xmldb_field->getName();
         /// Lets clean a bit each constraint description, looking for the filtered field
             foreach ($results as $key => $result) {
-            /// description starts by "$filter IN" assume it's a constraint beloging to the field
+            /// description starts by "$filter IN" assume it's a constraint belonging to the field
                 if (preg_match("/^{$filter} IN/i", $result->description)) {
                     $filtered_results[$key] = $result;
                 }
diff --git a/lib/ddl/postgres_sql_generator.php b/lib/ddl/postgres_sql_generator.php
index 35483fd7828..dc93e2a2a77 100644
--- a/lib/ddl/postgres_sql_generator.php
+++ b/lib/ddl/postgres_sql_generator.php
@@ -30,7 +30,7 @@ require_once($CFG->libdir.'/ddl/sql_generator.php');
 
 /// This class generate SQL code to be used against PostgreSQL
 /// It extends XMLDBgenerator so everything can be
-/// overriden as needed to generate correct SQL.
+/// overridden as needed to generate correct SQL.
 
 class postgres_sql_generator extends sql_generator {
 
@@ -49,10 +49,10 @@ class postgres_sql_generator extends sql_generator {
     public $enum_inline_code = false; //Does the generator need to add inline code in the column definition
 
     public $rename_index_sql = 'ALTER TABLE OLDINDEXNAME RENAME TO NEWINDEXNAME'; //SQL sentence to rename one index
-                                      //TABLENAME, OLDINDEXNAME, NEWINDEXNAME are dinamically replaced
+                                      //TABLENAME, OLDINDEXNAME, NEWINDEXNAME are dynamically replaced
 
     public $rename_key_sql = null; //SQL sentence to rename one key (PostgreSQL doesn't support this!)
-                                          //TABLENAME, OLDKEYNAME, NEWKEYNAME are dinamically replaced
+                                          //TABLENAME, OLDKEYNAME, NEWKEYNAME are dynamically replaced
 
     /**
      * Reset a sequence to the id field of a table.
@@ -95,7 +95,7 @@ class postgres_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one XMLDB Type, lenght and decimals, returns the DB proper SQL type
+     * Given one XMLDB Type, length and decimals, returns the DB proper SQL type
      */
     public function getTypeSQL($xmldb_type, $xmldb_length=null, $xmldb_decimals=null) {
 
@@ -196,7 +196,7 @@ class postgres_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to alter the field in the table
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to alter the field in the table
      * PostgreSQL has some severe limits:
      *     - Any change of type or precision requires a new temporary column to be created, values to
      *       be transfered potentially casting them, to apply defaults if the column is not null and
@@ -315,7 +315,7 @@ class postgres_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to drop its enum
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to drop its enum
      * (usually invoked from getModifyEnumSQL()
      *
      * TODO: Moodle 2.1 - drop in Moodle 2.1
@@ -334,7 +334,7 @@ class postgres_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to create its default
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to create its default
      * (usually invoked from getModifyDefaultSQL()
      */
     public function getCreateDefaultSQL($xmldb_table, $xmldb_field) {
@@ -344,7 +344,7 @@ class postgres_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to drop its default
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to drop its default
      * (usually invoked from getModifyDefaultSQL()
      */
     public function getDropDefaultSQL($xmldb_table, $xmldb_field) {
@@ -354,7 +354,7 @@ class postgres_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table returns one array with all the check constrainsts
+     * Given one xmldb_table returns one array with all the check constraints
      * in the table (fetched from DB)
      * Optionally the function allows one xmldb_field to be specified in
      * order to return only the check constraints belonging to one field.
@@ -390,7 +390,7 @@ class postgres_sql_generator extends sql_generator {
                 $description = preg_replace('/::[a-z]+/i', '', $description);              // Casts out
                 $description = preg_replace("/({$filter})/i", '@$1@', $description);
                 $description = trim(preg_replace('/ or /i', ' OR ', $description));        // Uppercase or & trim
-            /// description starts by @$filter@ assume it's a constraint beloging to the field
+            /// description starts by @$filter@ assume it's a constraint belonging to the field
                 if (preg_match("/^@{$filter}@/i", $description)) {
                     $filtered_results[$key] = $result;
                 }
diff --git a/lib/ddl/sql_generator.php b/lib/ddl/sql_generator.php
index ffad724a1b5..b1ae422a783 100644
--- a/lib/ddl/sql_generator.php
+++ b/lib/ddl/sql_generator.php
@@ -21,7 +21,7 @@
  * needed functions to generate proper SQL are defined.
  *
  * The rest of classes will inherit, by default, the same logic.
- * Functions will be overriden as needed to generate correct SQL.
+ * Functions will be overridden as needed to generate correct SQL.
  *
  * @package    moodlecore
  * @subpackage DDL
@@ -31,7 +31,7 @@
  */
 
 /**
- * Abstract sql generator class, base for all bd specific implementations.
+ * Abstract sql generator class, base for all db specific implementations.
  */
 abstract class sql_generator {
 
@@ -94,10 +94,10 @@ abstract class sql_generator {
                                   //MySQL CONCAT function will be used
 
     public $rename_table_sql = 'ALTER TABLE OLDNAME RENAME TO NEWNAME'; //SQL sentence to rename one table, both
-                                  //OLDNAME and NEWNAME are dinamically replaced
+                                  //OLDNAME and NEWNAME are dynamically replaced
 
     public $drop_table_sql = 'DROP TABLE TABLENAME'; //SQL sentence to drop one table
-                                  //TABLENAME is dinamically replaced
+                                  //TABLENAME is dynamically replaced
 
     public $alter_column_sql = 'ALTER TABLE TABLENAME ALTER COLUMN COLUMNSPECS'; //The SQL template to alter columns
 
@@ -108,16 +108,16 @@ abstract class sql_generator {
     public $alter_column_skip_notnull = false; //The generator will skip the null/notnull clause on alter columns
 
     public $rename_column_sql = 'ALTER TABLE TABLENAME RENAME COLUMN OLDFIELDNAME TO NEWFIELDNAME';
-                                  ///TABLENAME, OLDFIELDNAME and NEWFIELDNAME are dianmically replaced
+                                  ///TABLENAME, OLDFIELDNAME and NEWFIELDNAME are dyanmically replaced
 
     public $drop_index_sql = 'DROP INDEX INDEXNAME'; //SQL sentence to drop one index
-                                  //TABLENAME, INDEXNAME are dinamically replaced
+                                  //TABLENAME, INDEXNAME are dynamically replaced
 
     public $rename_index_sql = 'ALTER INDEX OLDINDEXNAME RENAME TO NEWINDEXNAME'; //SQL sentence to rename one index
-                                  //TABLENAME, OLDINDEXNAME, NEWINDEXNAME are dinamically replaced
+                                  //TABLENAME, OLDINDEXNAME, NEWINDEXNAME are dynamically replaced
 
     public $rename_key_sql = 'ALTER TABLE TABLENAME CONSTRAINT OLDKEYNAME RENAME TO NEWKEYNAME'; //SQL sentence to rename one key
-                                  //TABLENAME, OLDKEYNAME, NEWKEYNAME are dinamically replaced
+                                  //TABLENAME, OLDKEYNAME, NEWKEYNAME are dynamically replaced
 
     public $prefix;         // Prefix to be used for all the DB objects
 
@@ -590,7 +590,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to add the field to the table
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to add the field to the table
      */
     public function getAddFieldSQL($xmldb_table, $xmldb_field, $skip_type_clause = NULL, $skip_default_clause = NULL, $skip_notnull_clause = NULL) {
 
@@ -618,7 +618,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to drop the field from the table
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to drop the field from the table
      */
     public function getDropFieldSQL($xmldb_table, $xmldb_field) {
 
@@ -635,7 +635,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to alter the field in the table
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to alter the field in the table
      */
     public function getAlterFieldSQL($xmldb_table, $xmldb_field, $skip_type_clause = NULL, $skip_default_clause = NULL, $skip_notnull_clause = NULL) {
 
@@ -669,7 +669,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to modify the default of the field in the table
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to modify the default of the field in the table
      */
     public function getModifyDefaultSQL($xmldb_table, $xmldb_field) {
 
@@ -701,9 +701,9 @@ abstract class sql_generator {
     /// that we aren't trying to rename one "id" field. Although it could be
     /// implemented (if adding the necessary code to rename sequences, defaults,
     /// triggers... and so on under each getRenameFieldExtraSQL() function, it's
-    /// better to forbide it, mainly because this field is the default PK and
+    /// better to forbid it, mainly because this field is the default PK and
     /// in the future, a lot of FKs can be pointing here. So, this field, more
-    /// or less, must be considered inmutable!
+    /// or less, must be considered immutable!
         if ($xmldb_field->getName() == 'id') {
             return array();
         }
@@ -722,7 +722,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_key, return the SQL statements needded to add the key to the table
+     * Given one xmldb_table and one xmldb_key, return the SQL statements needed to add the key to the table
      * note that undelying indexes will be added as parametrised by $xxxx_keys and $xxxx_index parameters
      */
     public function getAddKeySQL($xmldb_table, $xmldb_key) {
@@ -763,7 +763,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_index, return the SQL statements needded to drop the index from the table
+     * Given one xmldb_table and one xmldb_index, return the SQL statements needed to drop the index from the table
      */
     public function getDropKeySQL($xmldb_table, $xmldb_key) {
 
@@ -830,7 +830,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_key, return the SQL statements needded to rename the key in the table
+     * Given one xmldb_table and one xmldb_key, return the SQL statements needed to rename the key in the table
      * Experimental! Shouldn't be used at all!
      */
 
@@ -867,7 +867,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_index, return the SQL statements needded to add the index to the table
+     * Given one xmldb_table and one xmldb_index, return the SQL statements needed to add the index to the table
      */
     public function getAddIndexSQL($xmldb_table, $xmldb_index) {
 
@@ -876,7 +876,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_index, return the SQL statements needded to drop the index from the table
+     * Given one xmldb_table and one xmldb_index, return the SQL statements needed to drop the index from the table
      */
     public function getDropIndexSQL($xmldb_table, $xmldb_index) {
 
@@ -895,7 +895,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_index, return the SQL statements needded to rename the index in the table
+     * Given one xmldb_table and one xmldb_index, return the SQL statements needed to rename the index in the table
      * Experimental! Shouldn't be used at all!
      */
     function getRenameIndexSQL($xmldb_table, $xmldb_index, $newname) {
@@ -1025,12 +1025,12 @@ abstract class sql_generator {
                  $fields = $statement->getFieldsFromInsertSentence($sentence);
              /// Get the values of fields
                  $values = $statement->getValuesFromInsertSentence($sentence);
-             /// Look if we have some CONCAT value and transform it dinamically
+             /// Look if we have some CONCAT value and transform it dynamically
                  foreach($values as $key => $value) {
                  /// Trim single quotes
                      $value = trim($value,"'");
                      if (stristr($value, 'CONCAT') !== false){
-                     /// Look for data between parentesis
+                     /// Look for data between parenthesis
                          preg_match("/CONCAT\s*\((.*)\)$/is", trim($value), $matches);
                          if (isset($matches[1])) {
                              $part = $matches[1];
@@ -1065,7 +1065,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one array of elements, build de proper CONCAT expresion, based
+     * Given one array of elements, build de proper CONCAT expression, based
      * in the $concat_character setting. If such setting is empty, then
      * MySQL's CONCAT function will be used instead
      */
@@ -1100,7 +1100,7 @@ abstract class sql_generator {
      * Only some DB have this implemented
      */
     public function isNameInUse($object_name, $type, $table_name) {
-        return false; //For generators not implementing introspecion,
+        return false; //For generators not implementing introspection,
                       //we always return with the name being free to be used
     }
 
@@ -1127,7 +1127,7 @@ abstract class sql_generator {
     abstract public function getDropTempTableSQL($xmldb_table);
 
     /**
-     * Given one XMLDB Type, lenght and decimals, returns the DB proper SQL type
+     * Given one XMLDB Type, length and decimals, returns the DB proper SQL type
      */
     public abstract function getTypeSQL($xmldb_type, $xmldb_length=null, $xmldb_decimals=null);
 
@@ -1166,7 +1166,7 @@ abstract class sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to drop its enum
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to drop its enum
      * (usually invoked from getModifyEnumSQL()
      *
      * TODO: Moodle 2.1 - Drop getDropEnumSQL()
@@ -1174,7 +1174,7 @@ abstract class sql_generator {
     public abstract function getDropEnumSQL($xmldb_table, $xmldb_field);
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to drop its default
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to drop its default
      * (usually invoked from getModifyDefaultSQL()
      *
      * TODO: Moodle 2.1 - Drop getDropDefaultSQL()
@@ -1191,7 +1191,7 @@ abstract class sql_generator {
     public abstract function getCheckConstraintsFromDB($xmldb_table, $xmldb_field=null);
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to add its default
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to add its default
      * (usually invoked from getModifyDefaultSQL()
      */
     public abstract function getCreateDefaultSQL($xmldb_table, $xmldb_field);
diff --git a/lib/ddl/sqlite_sql_generator.php b/lib/ddl/sqlite_sql_generator.php
index 56bb04a0339..a299a1d4a9e 100644
--- a/lib/ddl/sqlite_sql_generator.php
+++ b/lib/ddl/sqlite_sql_generator.php
@@ -29,7 +29,7 @@ require_once($CFG->libdir.'/ddl/sql_generator.php');
 
 /// This class generate SQL code to be used against SQLite
 /// It extends XMLDBgenerator so everything can be
-/// overriden as needed to generate correct SQL.
+/// overridden as needed to generate correct SQL.
 
 class sqlite_sql_generator extends sql_generator {
 
@@ -57,13 +57,13 @@ class sqlite_sql_generator extends sql_generator {
     public $enum_extra_code = false; //Does the generator need to add extra code to generate code for the enums in the table
 
     public $drop_index_sql = 'ALTER TABLE TABLENAME DROP INDEX INDEXNAME'; //SQL sentence to drop one index
-                                                               //TABLENAME, INDEXNAME are dinamically replaced
+                                                               //TABLENAME, INDEXNAME are dynamically replaced
 
     public $rename_index_sql = null; //SQL sentence to rename one index (MySQL doesn't support this!)
-                                      //TABLENAME, OLDINDEXNAME, NEWINDEXNAME are dinamically replaced
+                                      //TABLENAME, OLDINDEXNAME, NEWINDEXNAME are dynamically replaced
 
     public $rename_key_sql = null; //SQL sentence to rename one key (MySQL doesn't support this!)
-                                      //TABLENAME, OLDKEYNAME, NEWKEYNAME are dinamically replaced
+                                      //TABLENAME, OLDKEYNAME, NEWKEYNAME are dynamically replaced
 
     /**
      * Creates one new XMLDBmysql
@@ -127,7 +127,7 @@ class sqlite_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one XMLDB Type, lenght and decimals, returns the DB proper SQL type
+     * Given one XMLDB Type, length and decimals, returns the DB proper SQL type
      */
     public function getTypeSQL($xmldb_type, $xmldb_length=null, $xmldb_decimals=null) {
 
@@ -265,15 +265,15 @@ class sqlite_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to alter the field in the table
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to alter the field in the table
      */
     public function getAlterFieldSQL($xmldb_table, $xmldb_field, $skip_type_clause = NULL, $skip_default_clause = NULL, $skip_notnull_clause = NULL) {
         return $this->getAlterTableSchema($xmldb_table, $xmldb_field, $xmldb_field);
     }
 
     /**
-     * Given one xmldb_table and one xmldb_key, return the SQL statements needded to add the key to the table
-     * note that undelying indexes will be added as parametrised by $xxxx_keys and $xxxx_index parameters
+     * Given one xmldb_table and one xmldb_key, return the SQL statements needed to add the key to the table
+     * note that underlying indexes will be added as parametrised by $xxxx_keys and $xxxx_index parameters
      */
     public function getAddKeySQL($xmldb_table, $xmldb_key) {
         $xmldb_table->addKey($xmldb_key);
@@ -281,7 +281,7 @@ class sqlite_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to create its enum
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to create its enum
      * (usually invoked from getModifyEnumSQL()
      */
     public function getCreateEnumSQL($xmldb_table, $xmldb_field) {
@@ -289,7 +289,7 @@ class sqlite_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to drop its enum
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to drop its enum
      * (usually invoked from getModifyEnumSQL()
      */
     public function getDropEnumSQL($xmldb_table, $xmldb_field) {
@@ -297,7 +297,7 @@ class sqlite_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to create its default
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to create its default
      * (usually invoked from getModifyDefaultSQL()
      */
     public function getCreateDefaultSQL($xmldb_table, $xmldb_field) {
@@ -307,7 +307,7 @@ class sqlite_sql_generator extends sql_generator {
     /**
      * Given one correct xmldb_field and the new name, returns the SQL statements
      * to rename it (inside one array)
-     * SQLite is pretty diferent from the standard to justify this oveloading
+     * SQLite is pretty different from the standard to justify this overloading
      */
     public function getRenameFieldSQL($xmldb_table, $xmldb_field, $newname) {
         $oldfield = clone($xmldb_field);
@@ -316,7 +316,7 @@ class sqlite_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_index, return the SQL statements needded to rename the index in the table
+     * Given one xmldb_table and one xmldb_index, return the SQL statements needed to rename the index in the table
      */
     function getRenameIndexSQL($xmldb_table, $xmldb_index, $newname) {
     /// Get the real index name
@@ -328,7 +328,7 @@ class sqlite_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_key, return the SQL statements needded to rename the key in the table
+     * Given one xmldb_table and one xmldb_key, return the SQL statements needed to rename the key in the table
      * Experimental! Shouldn't be used at all!
      */
     public function getRenameKeySQL($xmldb_table, $xmldb_key, $newname) {
@@ -339,14 +339,14 @@ class sqlite_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to drop the field from the table
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to drop the field from the table
      */
     public function getDropFieldSQL($xmldb_table, $xmldb_field) {
         return $this->getAlterTableSchema($xmldb_table, NULL, $xmldb_field);
     }
 
     /**
-     * Given one xmldb_table and one xmldb_index, return the SQL statements needded to drop the index from the table
+     * Given one xmldb_table and one xmldb_index, return the SQL statements needed to drop the index from the table
      */
     public function getDropIndexSQL($xmldb_table, $xmldb_index) {
         $xmldb_table->deleteIndex($xmldb_index->getName());
@@ -354,7 +354,7 @@ class sqlite_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_index, return the SQL statements needded to drop the index from the table
+     * Given one xmldb_table and one xmldb_index, return the SQL statements needed to drop the index from the table
      */
     public function getDropKeySQL($xmldb_table, $xmldb_key) {
         $xmldb_table->deleteKey($xmldb_key->getName());
@@ -362,7 +362,7 @@ class sqlite_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table and one xmldb_field, return the SQL statements needded to drop its default
+     * Given one xmldb_table and one xmldb_field, return the SQL statements needed to drop its default
      * (usually invoked from getModifyDefaultSQL()
      */
     public function getDropDefaultSQL($xmldb_table, $xmldb_field) {
@@ -377,7 +377,7 @@ class sqlite_sql_generator extends sql_generator {
     }
 
     /**
-     * Given one xmldb_table returns one array with all the check constrainsts
+     * Given one xmldb_table returns one array with all the check constraints
      * in the table (fetched from DB)
      * Optionally the function allows one xmldb_field to be specified in
      * order to return only the check constraints belonging to one field.