how do i know if someone has read my messages on facebook?

[anonamous23]

well i sent a friend request to dis guy i like but he doesnt add me so i delete it, i try to send him a message but it fails, i try to get ova him but it was eid and a friend suggested i should message him to say happy eid i do and it gets sent a couple days later i send a msg to tell him how i feel about him any way how do i know if hes ignoring them or hasnt read them yet they both have arrows on them im not sure what they mean, ive told my friends about him and they think that he likes me and think that he will get bck to me but i want to move on is he ignoring me or not thank you in advance

[Vikz]

He has to accept your request if u want to know that he has read your message

[Sarah]

It will say seen at - whenever. But this guy seems to be ignoring you..