What characterizes irregular words?

Irregular words are characterized by the fact that they cannot be decoded through standard phonetic rules, meaning they do not follow typical patterns of spelling and pronunciation. This makes it challenging for readers to sound them out correctly based solely on their phonetic components. For example, words like "said" or "have" do not adhere to standard phonetic decoding rules, making them irregular. Recognizing these words is essential for fluent reading, as they often appear frequently in texts but must be memorized rather than sounded out.

Other options such as the ability to decode by sounding out or the presence of an onset do not define irregular words accurately, as these features apply to regular words that follow predictable sound patterns. Additionally, while many irregular words tend to be high-frequency, not all high-frequency words are irregular, making that characteristic not universally applicable.