1. run this command (a2enmod == apache2 enable module):

   a2enmod rewrite

2. edit this file /etc/apache2/sites-enabled/000-default; you can use the following command:

   sudo gedit /etc/apache2/sites-enabled/000-default

3. make sure you have there AllowOverride All directive for the default directory (this will make all the subdirectories inherit this behaviour):

   DocumentRoot /var/www
   	<Directory />
   		Options FollowSymLinks
   		AllowOverride All
   	</Directory>
   	<Directory /var/www/>
   		Options Indexes FollowSymLinks MultiViews
   		AllowOverride All
   		Order allow,deny
   		allow from all
   	</Directory>
   

4. restart apache and enjoy!

   sudo /etc/init.d/apache2 restart

Note: I use gedit because it’s my home desktop computer. On a server where you have no graphical interface at your disposal (and no gedit for that matter), you can safely use you favorite editor (nano, pico, vi) so all you have to do is replace

sudo gedit

with

sudo nano

if your favorite is nano.