Keyboard shortcuts let you quickly perform tasks in one step, without reaching for the mouse or finding a command on the ribbon.

You’re probably already familiar with a few keyboard shortcuts, like Ctrl+S, Ctrl+C, Ctrl+X, and Ctrl+V, which are the Windows shortcuts for save, copy, cut, and paste. Here are some more time-saving shortcuts when you're using Word on a Windows computer (U.S. keyboard layout):

Writing and formatting

Insert hyperlink

Ctrl+K

Undo

Ctrl+Z

Redo

Ctrl+Y

Select all  

Ctrl+A

Bold

Ctrl+B

Italics

Ctrl+I

Underline

Ctrl+U

Find what you need quickly

Find

Ctrl+F

Find and replace

Ctrl+H

                

Print

Print

Ctrl+P 

              

Get help

Open the Tell me search box

Alt+Q

Source: Microsoft