What defines irregular words?

Irregular words are defined by their unpredictable spelling-to-sound correspondence, meaning that the letters do not create the sounds we would typically expect based on phonetic rules. This occurs when the letters in the word produce sounds that are not commonly associated with those particular letters. For example, in the word “colonel,” the letters do not correspond to how it is typically pronounced, making it irregular.

The other options do not accurately capture the nature of irregular words. The first choice refers to words that align with their common sounds, which does not fit the criteria for irregularity. The second choice suggests phonetically predictable words, indicating that these words follow regular phonetic rules, which contradicts the definition of being irregular. The final option implies a limitation on parts of speech, while irregular words can include nouns, verbs, and other types, and their irregularity is not dependent on their grammatical category.