You can no longer see the person’s profile photo
You can no longer see their last seen or online status
Their status updates are no longer visible to you
Messages you send show only one check mark and never become two check marks
You cannot call them on WhatsApp
You cannot add them to a group
Their profile info may appear unchanged for a long time
You may notice that their contact details are no longer updating in the chat
If you try to message them from another account and it works, you may be blocked on your original account