Yes, simply put the '@' and then their username in your tweet.
Yes it does.
You receive a tweet when someone mentions you in their tweet.
To send a tweet, type a message in the large box at the top of the screen under the "What's Happening?". To mention a user in your tweet then type @username (replacing username with their actual username). Finish by clicking send to publish the tweet.
When you send someone a tweet using Twitlonger your tweet will end with a link that someone can click on to read the rest of your tweet. They can't access anything in your account they will only be able to view the tweet.
You can send a tweet to someone by beginning your tweet with their username (@username)
Simply start your tweet with the '@' symbol and their username.
There is no problem with reply to an old tweet by someone famous.
If you mention someone in a tweet, it can still be seen by everyone. Only direct messages are private.
Yes. As long as you don't start the tweet with the persons username and mention them in the body of the tweet.
No it will be deleted from their mentions too. Unless they received an email notification from the original tweet. *others may say it still comes as a notification but they can't get to it, that was in the past, the one that Erik Gruber posted is current.
If someone that DOES follow you retweets you and someone sees that tweet on their TL they will RT you.. and they don't have to be following you... Follow me @ALexisU_
If your tweets are protected then the "retweet" button is not available on your tweets. However, this doesn't stop someone who is following you from copy and pasting your tweet to a new tweet and adding "RT" before it.