On iMac (OS X):

  1. Open “System Preferences” and click “Languages and Text”
  2. Choose “Input Sources” from the top menu
  3. Choose “Chinese – Traditional Pinyin” to add a new keyboard
  4. Select the “Show Input Menu In Menu Bar” check box

On Mac iPhone, iPad (iOS):

  1. Open “Settings” and click “General”
  2. Scroll down and choose “Keyboard”
  3. Click “International Keyboard” and click “Add New Keyboard”
  4. Choose “Chinese – Traditional Pinyin” to add a new keyboard

You should now be able to switch languages using the “regional key” (lower left on the soft keyboard).

Learn how to start Typing in Chinese.