At the other end of the scale were Spanish, with a density of .63 and a speed of 7.82, and Japanese, with a density of only .49 but a speed of 7.84.

So what makes a language more or less dense? The number of sounds, for one thing. Some languages make do with relatively few consonants and vowels, and so end up with a lot of long words: Hawaiian, for example, with 13 letters. Those fast-talking Japanese! And Spanish! –