In ch. 4 of "To Kill a Mockingbird" what shows Scout they're watched? What 3 things have already happened to support this view?
At the end of chapter 4, Scout says that after she had fallen out of the tire in the Radley's yard, that "someone inside the house was laughing." So that is evidence that they were being watched, and that someone obviously found Scout's being launched out of the tire a pretty amusing spectacle.
Previous evidence to support that they were being watched consist of the fact that Scout found a piece of chewing gum in the tree in front of the Radley house. After that first time, they also find a ring-box with pennies inside. So someone knew that they walked right by that tree every day, and was leaving things for them to find. So, not only are they watched, but someone is extending a hand of friendship. Then, at the end of chapter one, after Jem slaps the side of the Radley house, they "thought [they] saw an inside shutter move. Flick. A tiny, almost invisible movement." If it had indeed moved, that means that someone had been watching them in their game.