Cancel sending a message to group in WhatsApp I mistakenly pasted a message in a WhatsApp group. I noticed that immediately and turned off my internet. The message was still not sent (single tick did not appear), and I deleted that message and turned on the internet.

Will this stop the message from getting sent to the group?
The single tick means the message was sent to WhatsApp servers and, once it gets there, you can't cancel it.

Your only chance to cancel a message is when it still has a clock sign on the bubble -- meaning it didn't reach the servers yet. To do that, you press and hold the message and then delete it.