Have you ever wondered which form is more correct? “Sneaked” or “snuck”? Well, of course “sneaked” is British English and “snuck” is used by Americans, so discussing correctness does not really make much sense. But which form is the “original one”?
In language change forms often tend to become regular from irregular by means of “analogy”. So, “snuck” should have a good chance of being the original form. If you compare the two forms on Google Books Ngram Viewer, you will actually find out that the reverse is true: “snuck” sneaked into literary language sometime around the 1920s and started to become really popular in the 1980s (see image) (very likeley through a process called "hypercorrection" by linguists).
Google Books Ngram Viewer is a part of Google labs that lets you visualize the frequency of words in all 5 million books from 1800-2000 scanned by Google. There are many more creative ways of using this technology as shown in this hilarious episode of Ted Talks titled “What we learned from 5 million books”.