I like to hear the clicking when I type. Some times it clicks and sometimes it does not. I am not aware of changing any settings so why does the clicking come and go. Thanks for an answer!

If you have the Mute switch turned on it will stop all system sounds, including the keyboard sounds.

iPad: Understanding the side switch

I have noticed this too????it's not the mute switch because that is always turned on..

There are only two things that control the the keyboard click. One is Mute (not always the side switch, and covered in my previous link), the other is the the settings of Settings > General > Sounds. Here you must have it turned on. Also notice that you can make the system sounds volume independent of the main volume level (Change with Buttons: OFF), or have it tied to the iPad's overall volume level (ON) In the second case if you've turned the iPad's volume down too far you won't hear the system sounds.