By clicking on 'reply' or starting a tweet from scratch and starting it with their username (@username).
Tweet them.
You can tweet someone even if their account is protected.
Send them a tweet and ask them nicely.
You can't make someone follow you. If you want him to follow you then you should tweet him and ask him to do so.
Begin your tweet with their username (@username)
you make a responce to the owner of which tweet you would like to comment on by putting @their user name and then your comment
Tweet, re-tweet, Follow Friday are all examples of terminology found on Twitter.
If they like what you tweet about.
Twitter alllows you to see the activity of people who you follow and they don't have to follow you back unlike facebook where it has to be mutual to see activity. Also twitter allows you to retweet a tweet that you particularly like instead of liking it on facebook. facebook allows you to comment on things but on twitter you have to tweet about the thing. Twitter and facebook are different in many way, those ones were just off the top of my head but personally i think that both are good accounts to have if you use theem regularly. Follow for Follow on twitter - hallowell_x
Send them a tweet and ask them.
Any Twitter user can send you a tweet if your account/tweets aren't protected.
You can send a tweet to someone by beginning your tweet with their username (@username)