For this assignment, I looked at a couple different Twitter pages from teachers at Fairfield Union High School to see how each teacher uses their Twitter.
Ms. Wilson (11th grade English): Her Twitter page looks fairly new, but it looks like she uses it for some reminders and some English jokes.
Ms. Cupp (12th grade English): This ones isn't maintained, but she used it more for class reminders.
FUHS Guidance Office: They tweet mainly due date reminders and other useful information regarding college applications, ACT, etc.
I have not seen the students using Twitter in either of the English classes.
Sources: Twitter pages (linked)