How to switch language keyboard combination?

I would like to type Hebrew in Ubuntu. I tried downloading the Hebrew language pack and then setting alt-shift as my layout-change shortcut in the Options section of "Keyboard Layout".

However, when I actually press alt-shift, nothing happens. How can I switch my keyboard layout to Hebrew?

Ubuntu 17.10 and newer (GNOME Shell)

From this answer: After adding the desired languages (by navigating to Settings -> Regional & Language), you can use the default keyboard shortcut which is Super+Space ("super" is another name for the Windows key), or you can click on the top bar menu:

Ubuntu 13.10 to 17.04 (Unity)

As of Ubuntu 13.10, it is now called Text Entry Settings instead of Keyboard Layout

It can be reached through either of these methods

1. Going through System Settings -> Text Entry
2. Using the App Indicator as shown in the screen-shot below.

Ubuntu 13.04 and older

Seems you forgot an important step.

1. Download Hebrew language support. You can do this from the Install/Remove Languages section of "Language Support".
2. System Settings -> Keyboard Layout -> "+" -> "Hebrew" -> Add
3. System Settings -> Keyboard Layout -> Options -> Keys to Change Layout -> mark [alt]+[shift] (this step is optional, only if you want that custom keyboard shortcut)

An icon like this should appear in the upper-right after step two:

To switch keyboard layout on Ubuntu 12.04

1. Go to System Settings...

2. Under Keyboard Layout - click on Options...

   

3. Under Key(s) to change layout - choose the combination of keys you would like to use.