[blubber12]

ok part of your problem is that you can't manually add that query as written "table prefix" is catchall relating to whatever your table prefix is. Run this instead

ALTER TABLE usergroup ADD shoutboxpermissions INT UNSIGNED NOT NULL DEFAULT '0' AFTER forumpermissions

and

ALTER TABLE language ADD phrasegroup_shoutbox MEDIUMTEXT NOT NULL
ALTER TABLE language ADD phrasegroup_shoutmanager MEDIUMTEXT NOT NULL

Now, if your tables DO have a prefix...you must add it to the table name ie prefix.language or whatever it is you use. Most probably don't have a specific prefix and just use the server default..so you should be ok to run the above