Im sorry, but wat i mean is,for the first time i acces root's permission, yes it asks me 4 the root's password. But after that, it doesnt. N thats wat i wanna change. I want it 2 ask me the password every time.
In that case, you want to modify the timestamp_timeout value in the /etc/sudoers file. Open up the sudoers file with
$ sudo visudo
enter your password, then look in the file for a line that starts with Defaults and has timestamp_timeout in it. Adjust the value so that it's set to 0. If there isn't a line like that present in the file, add a new one: