Click the number of line spaces that you want, selected text appears in double spacing
3
Click 2.0 - To double-space the selected paragraph
and see the effect on the selection.
 
Let's see the effect of single spacing
4
On the Home tab, in the Paragraph group, click Line Spacing.

Click on 1.0 for single-spacing
 
Selected text appears in single spacing
5
Click anywhere in the document to remove the text highlighting.