Let’s get straight to it and add one now. On the Insert tab, click Shapes (in the Illustrations group) > Oval Callout. The shapes are not visibly named, but the Oval Callout shape is in the Callouts section near the bottom.

Clicking the shape doesn’t insert it; it simply activates the tool. You still need to draw the shape on the page by clicking and dragging in your document. Once you’ve clicked and dragged, you should get something like this:

This is all well and good if you want something quick. We, on the other hand, are genteel and sophisticated. We desire a speech bubble that has a curved bit like this:

We can make that curve by manipulating the points on the shape. If you’ve used image editors like Adobe Illustrator or Fireworks, this should be a doddle. If you haven’t, don’t worry because it’s quite easy anyway.

With the speech bubble still selected, make sure you’re working on the Format tab of the Drawing Tools contextual tab (it pops up whenever a shape is selected).

Click Edit Shape (in the Insert Shapes group) > Edit Points. You’ll notice that the bounding box for the shape has gone. Each point that defines the shape is also now selectable and able to be manipulated.

Click on the point right at the bottom and drag it further down. Because this point is now selected, you should see some yellow handles that you can drag around to alter the curve of the lines coming out of that point.

Try it. Drag those handles around to get a feel for how they affect the curvature. Those handles affect the curve of the lines near the selected point. To change the curvature of a line near the point at the other end, select that point and repeat the process. This is often necessary to achieve a nice smoothe curve.

To get the following speech bubble, drag the yellow handle on the right upwards and to the right. Do the same with the yellow handle on the left.

The curve looks fine as it leaves the bottom point, but it soon goes awry further up. We can fix that by selecting the point (click on it) and then by dragging the leftmost yellow handle to the right. You can even drag the point itself over to the right to get something like this: