Quam = "than." The origin of this construction is obscure, but Latinists guess that it was the result of confusing two common expression. The first is the typical way in which Latin compares two things that are not different: "I am as happy as he" = ego tam beatus sum quam ille. This sentence was originally two sentences: "So happy I am. He is as happy." in which tam = "as" or "to that degree" and quam has its original meaning "as." (Note: tam is a demonstrative = to that degree; quam is a relative = to what degree.) tam ego beatus sum. quam ille beatus est. These two sentences would be readily conflated and the redundant "beatus est" ellipted (or skipped over) as follows: ego tam beatus sum quam ille. So, now we have a standard way of comparing similar things. The second common expression is Latin's original way of comparing dissimilar things: the Ablative of Comparison. ego beatior sum illo. Linguists believe that the Romans simply confused the construction that followed ego beatior sum with the construction that followed ego tam beatus sum. Both were comparisons: "I am happier" or "I am as happy" ... "as he."