There are two ways to do this. The first is Insert + numpad 5 twice
quickly. If you are using a laptop Capslock + K twice quickly will
work as well. The second way is to press F2. This will put you in Edit
mode. You can press the home key to go to the beginning of the cell
and right arrow to spell the content. Remember this is an edit field
and you can make changes if you press a key by accident.

Allen