\!h Simplest form - check current user's privileges:
SHOW GRANTS;
+-------------------------------------------------------------------------------------------------------------+
| Grants for dave@localhost                                                                                   |
+-------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'dave'@'localhost' IDENTIFIED BY PASSWORD '*2470C0C06DEE42FD1618BB99005ADCA2EC9D1E19' |
| GRANT ALL PRIVILEGES ON `music`.* TO 'dave'@'localhost'                                                     |
+-------------------------------------------------------------------------------------------------------------+

\!h Check another user's privileges:
SHOW GRANTS FOR 'selina'@'localhost';

\!h mysqlaccess
-- Quickly check what level of access a particular user has for a particular database
-- example - partmusic's level of access for the 'music' db:
mysqlaccess --user=root --password=root_password partmusic music