Now here's a subtle detail of the Russian language. It's one that will trip you up at first when you start reading Russian if you aren't paying attention. Although большой means big, there is another word больший that means bigger, greater, or larger. Since Russians don't usually write stress marks, the presence of о or е after the ш is often the only written indication of which meaning is implied. Больший declines like this:

Sample sentences:

As part of your Russian reading strategy in your early years, you might want to pause when you come across большой and больший. If you spot a е after the ш, then remind yourself that it means “bigger.” That helps in the singular of most forms. Alas, only context can tell you which one the author had in mind in the plural.