How can you tell if somebody received and read your messengers from Facebook?

One thing I noticed when I send comments to friend on messenger. There is three hole next to messengers. First is check mark in blank, or check mark in fill in bold or check mark is gone and now this person picture profile now fill in that hole.

Often when that check mark is gone but profile picture then I get reply from them.

So what about check mark in empty or in fill in bold?

So how can I tell if they receive my message or didn't read my message?