Do one of the following:
Align objects with a guide
If the guides aren't displayed, click Grid and Guides on the View menu and select the Display drawing guides on screen check box.
Align objects on a grid
By default, any time you draw, resize, or move a shape or other object, it will position or snap to the lines in the grid. If the grid isn't displayed, click Grid and Guides on the View menu and select the Display grid on screen check box.
To automatically align objects on a grid, verify that the Snap objects to grid check box is selected.
To automatically align objects with grid lines that go through the vertical and horizontal edges of other shapes, verify that the Snap objects to other objects check box is selected.
Tip
To override the snap-to settings, press ALT as you drag or draw an object.