You can use Twitter at any age because twitter,unlike other Social Networking sites,does not ask your Date of Birth and Gender.
You need an email address.
Twitter says you need to be 13,although they don't ask the age.
Twitter doesn't ask for your age while signing up but its privacy policy states that you need to be at least 13 years old to have Twitter.
You don't need twitter but it is better to make a twitter account just before your skype account so that you can use the same name
yes
You have to be 13 to have a twitter
He might need it to communicate with friends. It is aloud according to Twitters TOS.
Can a 9 year old have a twitter
There are no age requirements to have a Twitter account or use a Twitter account.
Yes you need internet on your phone for twitter
You must be 13 years old to create a Twitter account.
You can make trivias on twitter by searching some facts and then posting it on twitter :)