How to Format a message in Microsoft Teams
Desktop
Messages can be formatted in several ways.
Under the compose box, select Format to open your formatting options. If you want to bold, italicize, or underline the text, click the B, I, or U buttons in this expanded view.
In addition, you can highlight, change the font size, and create lists. You can attach a file or insert fun stuff like emojis by clicking More options.
Mobile
Open the text editor by tapping the Format button in the compose box. Underlining, italicizing, or bolding text is one of the many options available in the editor. The message can be rewritten without accidentally sending it, you can highlight text, change the color of the text, and mark the message as important by clicking the appropriate button.
The spelling errors you make as you type are highlighted in red by Teams. To see suggested corrections, right-click the error. The spelling and grammar checks in Teams are not separate (unless you are working on the Wiki).