sudo adduser john
You will be prompted for a password and for some additional information:
Adding user `john' ... Adding new group `john' (1001) ... Adding new user `john' (1001) with group `john' ... Creating home directory `/home/john' ... Copying files from `/etc/skel' ... Enter new UNIX password: Retype new UNIX password: passwd: password updated successfully Changing the user information for john Enter the new value, or press ENTER for the default Full Name []: John Room Number []: 1 Work Phone []: 555-555-5555 Home Phone []: Other []: Is the information correct? [Y/n] y