Many times when creating a PowerPoint slide, using the bulleted list format, you may need to extend your thought by creating a new line. By default, each time a new line is started, by pressing the Enter key, PowerPoint inserts a bullet to start the line. This can be easily avoided by manually inserting what is called a "soft return".
A soft return causes the text to drop to the next line automatically when it reaches the margin or edge of the text box. To force a soft return, you simply hold the Shift key while you press the Enter key at the same time. This will drop the insertion point to the next line, but will not add a new bullet.More Keyboard Shortcuts in PowerPoint