WhatsApp provides an option to mark chats as ‘unread’ to help us remind to reply to the messages we have left seen. You can reply to the messages that you have marked ‘unread’ whenever you get time. Once you open these messages, they will be marked read again.
It is vital to note here that marking a message as ‘unread’ only means that your messages are marked unread only for you. The sender will continue seeing the Blue Ticks indicating that you have read the messages but not replied.
How to mark WhatsApp chats unread :-
Swipe to the right on the chat(s) you desire to mark as unread…Read more>>