How do you send someone a "tweet" on twitter?

[indifferent]

Do you put "@" followed by the name of who you want to tweet then the message. how do you know they received it

[croakditch]

You are correct, their username prefixed with an "@" sign will send a message to them, but it will also display it on your main 'tweet' screen, which all who are following you can also read. If you would rather it remain private you can send a 'direct message' by going to their tweet page, and selecting 'message' on the right hand side of the screen.

[cory2107]

You are right, but that's an @reply. If you want to direct message type "d <their username> <your message>" (without quotes) to direct message.