Syntax:
SHOW GRANTS [FOR user]

This statement displays the privileges that are assigned to a MySQL
user account, in the form of GRANT statements that must be executed to
duplicate the privilege assignments.

*Note*:

To display nonprivilege information for MySQL accounts, use the SHOW
CREATE USER statement. See [HELP SHOW CREATE USER].

SHOW GRANTS requires the SELECT privilege for the mysql system
database, except to display privileges for the current user.

To name the account for SHOW GRANTS, use the same format as for the
GRANT statement (for example, 'jeffrey'@'localhost'):

mysql> SHOW GRANTS FOR 'jeffrey'@'localhost';
+------------------------------------------------------------------+
| Grants for jeffrey@localhost                                     |
+------------------------------------------------------------------+
| GRANT USAGE ON *.* TO `jeffrey`@`localhost`                      |
| GRANT SELECT, INSERT, UPDATE ON `db1`.* TO `jeffrey`@`localhost` |
+------------------------------------------------------------------+

The host part, if omitted, defaults to '%'. For additional information
about specifying account names, see
https://dev.mysql.com/doc/refman/5.7/en/account-names.html.

To display the privileges granted to the current user (the account you
are using to connect to the server), you can use any of the following
statements:

SHOW GRANTS;
SHOW GRANTS FOR CURRENT_USER;
SHOW GRANTS FOR CURRENT_USER();

If SHOW GRANTS FOR CURRENT_USER (or any equivalent syntax) is used in
definer context, such as within a stored procedure that executes with
definer rather than invoker privileges, the grants displayed are those
of the definer and not the invoker.

SHOW GRANTS does not display privileges that are available to the named
account but are granted to a different account. For example, if an
anonymous account exists, the named account might be able to use its
privileges, but SHOW GRANTS does not display them.

SHOW GRANTS output does not include IDENTIFIED BY PASSWORD clauses. Use
the SHOW CREATE USER statement instead. See [HELP SHOW CREATE USER].

URL: https://dev.mysql.com/doc/refman/5.7/en/show-grants.html

