If your outgoing messages are blue, the person can receive iMessages. If outgoing messages are green, the person is using a non-iMessage phone or tablet (usually an Android). You won’t be able to see when this person has read your messages. Group messages do not support Read Receipts.
Open your iPhone’s Settings. Scroll down and tap Messages. Slide the “Send Read Receipts” switch to the On (green) position.
To find a conversation with ease, you can pin an iMessage conversation.
You can also send a free text message.
When you send the message and it hasn’t been delivered, you’ll see a single gray check mark. This means the person you’re writing hasn’t opened WhatsApp since you sent the message. If the person has opened WhatsApp since you sent the message but hasn’t yet opened your message, you’ll see two gray check marks. When the person reads your message, the two check marks will turn blue.
This is also where you can delete messages from Messenger.
A blue check mark in a white circle means you’ve sent the message, but the person has not yet opened Messenger. A white check mark in a blue circle means the person has opened Messenger since you’ve sent the message, but they haven’t read it. When the person’s profile picture appears in a tiny circle below the message, you’ll know the message has been read.
