Extensive reading is reading as much as possible, for your own pleasure, at a difficulty level at which you can read smoothly and quickly without looking up words or translating to English as you go. In other words, instead of spending a half hour decoding a tiny part of one book (also known as intensive reading), you read many simpler books that are at or slightly below the level at which you read fluently. This lets you get used to reading more complex sentences with ease, reinforces the words you already know and helps you learn new words from context.