Just a plain old English "Five"
And the illness that is going around, providing you aren't suffering from it, makes for some interesting observations. Have you noticed that while the usually erudite Ravenclaws drop verbs and subjects and talk in dependent clauses (see Exhibit A: Roger Davies), the Hufflepuffs, unfairly labeled as "duffers" by some, have become more creative and loquacious (see Exhibit B: Beatrix Dunstan)? Except in the case of some, their opinions on interstudent relationships (see Exhibit C: Cadwallader)
That said, I have no wish to validate my hypothesis first-hand.