1. If a person has protected his tweets, and I do not follow him, I will not see his tweet even if he mentions me.

 

2. To get a direct link to a tweet, click on the time below each tweet (eg: “about 11 hours ago“).

3. To see which tweet has been responded to, click on the “in reply to” link below each tweet.

4. If you want to know whether a person follows you, one method (among others) is to visit his/her profile and see if you can Direct Message him/her. If s/he is not following you, the DM option will not be available in the list.

5. Rogue applications that you may have unknowingly given access to need to be removed from the Settings Connections to avoid untoward incidents.

Also read:
Are you a Twitter addict?

New to Twitter?