It is assumed languages of human beings are directed by rules; however, these rules have certain exceptions in the form of irregularities. A double-marked form in which the regular rule is added to an irregular form has been attested in languages of human beings and is considered as a type of irregularization in the morphological processing. It has been claimed that there is a correlation between this type of irregularization process and high word frequencies. The real rate and nature of these double-marked forms have rarely been documented. On the basis of data from the new linguistic corpus (WebCorp) which allows us to make refined searches given its wider range of searching possibilities, this paper investigates whether there is a correlation between these irregularization processes in the English verbal system and word frequency with the aim of addressing the research questions: Is there a relationship between irregularization with the type of double-marked forms and word frequency in current English? If so, are irregular verbs with high frequency irregularized more often than the ones with low frequency? To do so, word frequencies of 488 irregular verbs in the past and perfect were collected from the selected corpus. Then, word frequencies of their corresponding double-marked forms in both forms were collected from the same corpus. Descriptive and statistical analyses were conducted to test the importance of the difference in the results. 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