Every message you send in a one-to-one chat moves through 3 stages, shown by the tick marks next to it.
The 3 statuses
Sent (✓). Your message has left your device and reached PLAI's servers, but the other person's device hasn't received it yet, usually because they're offline.
Delivered (✓✓). The message has reached the other person's device, but they haven't opened the chat to view it yet.
Read (✓✓, coloured). The other person has opened the chat and viewed your message.
Note: A message is only marked "read" once the other person actually has it visible on their screen. Once a message is marked read, you can assume every message before it in the conversation has been read too.
FAQ
Can I turn off read receipts?
Not currently. Read status is a standard part of one-to-one chat on PLAI.
Why is my message still showing "sent" after a while?
The other person is most likely offline. Their status updates to "delivered" as soon as they reconnect.