This solution works for MS Word as well as MS Outlook, if MS Word is set as your word processor for MS Outlook. Please follow the following steps:
- Click on "View - Toolbars - Customize"
- Click on "Command" thumb guide
- Click on "Tools" in the left column
- Search for the "Language" option in the right column (not "Set Language", just the one below that)
- Click on "Language" and drag it to any of the existing toolbars
- Click "Close"
Now you only have to highlight the part of document that you want to change and choose the language you prefer out of the available list. It is as easy as that.