Use Snap to Grid 
to align objects to the Grid lines when they are drawn using Point Draw 
, Bezier Draw 
and Insert Shape 
, or when they are moved.
Select Snap to Grid
-
In the toolbar select Snap to Grid
. -
Choose Edit > Snap to Grid.
Closing Lines
You can join lines to themselves when using Freehand Draw
, Point Draw 
and Bezier Draw 
.
If a line is drawn close to its own starting point, then the mouse pointer will change to a cross 
.
If that line is completed while the pointer is a cross, the line will be closed to form an area that may be filled.