Three letter rule poets such as John Milton alternated between short and long forms for function words, depending on whether they occurred on or off the meter. For instance: While many function words have more than two letters ("and", "she", "were", "therefore", etc.), the exceptions to the rule are rather two-letter content words. Only a few of these occur commonly in most texts: the words "go" (which also has a functional usage in the idiom "going to do something"), "ox" and, especially in American texts, "ax". English grammar is relatively flexible about converting words of one class to another, allowing verbal uses such
Transposed letter effect are letter-position specific when detecting words, so our recognition of words is based on what letters it contains, where the letters are placed within that word and the length of the word itself. Another example is the bayesian reader model created by Norris (2006) which also assumes that the letters in a word are associated with their specific location. Many experiments (for example, Perea and Lupker, 2003) have shown if you use transposed-letter priming, (for example, priming judge with jugde) you will see a priming effect but if the prime is a word where two letters are changed to other