This wikiHow teaches you how to add a new user to an existing WhatsApp chat group.
Step
Step 1. Open WhatsApp Messenger
The WhatsApp icon looks like a green box with a white speech bubble and a phone receiver inside.
If WhatsApp immediately displays a page other than the “Chats” page, tap the “Chats” button
Step 2. Touch the chat group
On the “Chats” page, find and open the desired chat group.
Step 3. Touch the group name at the top of the chat thread
You will be taken to the “Group Info” page for the selected chat group.
Step 4. Touch Add Participants at the bottom of the page
Step 5. Swipe the screen and touch the name of the contact you want to add to the group
You can also use the “Search” function or feature to find friends. To use it, tap the “Search” field at the top of the screen and type in the friend's name
Step 6. Touch the name of the other contact you want to add
You can add one or more people at once.
Step 7. Touch the Add button
It's in the upper-right corner of the screen.
Step 8. Touch Add again to confirm selection
The selected contact will be added to the chat group.