Apple’s iPhone supports a literally exciting virtual keyboard that does its best to calculate what you are typing. In Apple iPhone the keyboard caps

lock feature is disabled defaultly. It even automatically activates the Shift key at the beginning of a sentence, and shuts it back off after you type the first letter. So it’s mandatory to hold down the shift key every time when you want to type letters in uppercase. The Caps Lock slider is like a toggle switch. Tapping it once enables the feature, tapping it a second time shuts it back off. You would like to enable the caps lock feature in iPhone OS4

1. Go to your Apple iPhone home screen and tap on Settings icon
2. Then tap the General button on the next screen
3. In the general settings screen, tap on the Keyboard button
4. In the keyboard settings screen, tap on or slide the switch to the right of Enable Caps Lock

If you quickly tap the shift key twice it will turn blue and showing that now caps lock mode is on