Character mistake: When you catch Andy recovering a bottle of elixir in the upper right corner of the hall, a conversation ensues. He then says "Oh, so it's not OK if I shrae it with your Mom", with a misspelling of "share."
Character mistake: When the protagonist goes fourth base with the teacher and the nun at the same time, he says "Oh God, Mrs. Bancroft! Your squeezing extra hard" with a basic grammar mistake.
Character mistake: "Contact lens" is consistently misspelled as "lense."
Character mistake: In the prologue, Buddy cautions the player "No wondering around." That'd be 'wandering'.
Character mistake: Throughout the whole game, a verb used quite extensively is misspelled as "mastErbate."
