Bill: He thr-thr-thr-thrusts his fi-fi-fists ag-ag-against the pos-posts and...
Ben: He thrusts his fists against the posts and still insists he sees the ghosts. That's all it says over and over.
Bill: Th-th-thats w-w-what m-m-my m-m-mom g-gave me t-to h-help with my st-st-stutter.
Richie: I hate to tell you buddy, it ain't working.
In the library scene when Richie sees Pennywise the clown, all the balloons filled with blood are popping on people who aren't supposed to be able to see them, but one lands on a lady and you can see her jump as the balloon pops.
Tim Curry admitted that while he enjoyed working on the film, he was ultimately disappointed by the finished product, mainly due to the ending. He felt the final creature (a massive spider) was poorly executed and a massive let-down, and lacked any sense of fear or suspense.