What does the WhatsApp grey tick mean and how to tell if your contacts have blocked you

dailystar.co.uk:

WhatsApp message can be nerve-wracking.In fact, it's almost as stressful as being left on 'read': where you've sent a message, you can see two blue ticks, and you know your contact has read what you've sent but still hasn't replied.Luckily, WhatsApp actually provides updates on the status of your message from the second you write it up until someone opens it and reads it.So let you go of your message anxiety with this handy guide to WhatsApp ticks and what they really mean.Most people know that two blue ticks mean a message has been read and received, but what about one grey tick?

One grey tick on a WhatsApp message simply means that the message has successfully sent from your phone, but it hasn't been delivered to the recipient yet.