Many common words present challenges to children because they are irregular in some way. An irregular word is a word that presents a challenge for decoding. These words contain elements that do not follow the most common letter-sound correspondences. Some words are permanently irregular. In these words, the sounds of the letters are unique to that word or to a very small number of words. Other words are temporarily irregular. This means that the student has not yet learned the letter-sound correspondences in the word.
Although irregular words can be challenging, there are effective methods for teaching them. The good news is that, in most common irregular words, only one or two letters don’t adhere to expected phoneme-grapheme correspondences. This means children can learn to decode most of the word, and they only have to learn one or two letters “by heart.” The Heart Words materials below can be used to teach irregular words this way. This approach can promote children’s orthographic mapping.
Once an irregular word has been introduced and taught, which includes sounding out the decodable parts and recognizing the part(s) that need to be learned by heart, flash cards can be an effective tool for practice. For many readers, irregular words are committed to memory after only a few (1-4) exposures. A struggling reader may need 20 or more exposures to the same word before it can be recognized on sight.
Here’s a helpful article about teaching irregular words.