The space bar is the long bar beneath the bottom row of keys
and is used to separate letters and words.  Use the thumb to 
strike the space bar.  Use the thumb that is most comfortable for
you.  Most people use their right thumb; however, some left 
handed people prefer to space with their left thumb.  But 
remember to always use the same thumb.  With all your fingers 
held above the home row keys, position the thumb that you plan to
use for spacing approximately one-fourth inch from the space bar.


The space bar should be tapped in its center.  Place the thumb 
you are not using where it does not interfere with the other 
fingers.