This article compares the word frequencies of the few most commonwords in Spanish as revealed by a modern corpus of over fivethousand words with a corpus of Golden-Age Spanish texts of overa million words, and finds that although de is by far themost common word in contemporary Spanish, in the 16thand 17th Centuries it was considerably less frequent, and in many texts was less frequent than y, or quefor which shared very similar frequency figures. It is arguedthat this significant change in the Spanish language comes aboutin the 20th Century.