Here’s how you can format text on WhatsApp:
Italic: To italicize your message, place an underscore on both sides of the text, like so:
_text_
Your text should now look like this:
text
Bold: To send text in bold, place an asterisk on both sides of the text, like so:
*text*
This will make your message appear like this:
text
Strikethrough: To strikethrough your message, place a tilde on both sides of the text, like so:
~text~
Your message will now look like this:text
Monospace: To monospace your message, place three backticks on both sides of the text, like so:
“`text“`
Your message will now look like this:
text
You can do this for either the entire message or just certain words or phrases. If these seem like too many steps to remember, then alternatively, both Android and iPhone users can tap and hold the text they’re typing and select the ‘More’ option > and choose among bold, italic, strikethrough and monospace.
Source: click here