 His advances have been attributed mainly to the influence of his contemporary Rasmus Christian Rask.Rask was two years younger than Grimm, but the Icelandic paradigms in Grimm's first editions, his Icelandic paradigms are based entirely on Rask's grammar; in his second edition, he relied almost entirely on Rask for Old English.His debt to Rask is shown by comparing his treatment of Old English in the two editions.