You can set double line-spacing through the menu - Format | Paragraph and in
the Spacing section under line-spacing select Double.
However a quicker way is to use the keyboard. Hold down the Ctrl key and
press 2 for double, Ctrl and 1 for single and Ctrl and 5 for one-and-a-half
linespacing.
If you are changing previously typed text, remember to select (highlight)
the text before using the command. Hope this helps.
