In Word Perfect File Menu go to Format and you will have a "Line" option. There is a little arrow next to "Line" which produces more choices, one of which is "Spacing. ". so using that command you can do double space between sentences
If the document is already typed up select/highligh the lines you want double spaced and on the keyboard press the Ctrl key + 2,
Ctrl + 1 brings it back to single spacing
Ctrl + 5 makes it 1. 5 line spacing.