Is the trigraph 'igh' considered regular for spelling?

The trigraph 'igh' is considered irregular for spelling because it does not follow the typical phonetic conventions that one might expect based on its constituent letters. In English, the trigraph 'igh' represents the long vowel sound /aɪ/, as in the words "high," "sigh," and "light." This sound can be misleading, as the 'g' and 'h' in this trigraph do not function as silent letters or contribute to the sound in a conventional way. Instead, 'igh' stands out because it does not conform to more predictable phonetic patterns found in other spelling rules, which often correlate letters more directly with their sounds. This irregularity means that the spelling of 'igh' does not provide the sound cues that would typically help learners predict the correct spelling, marking it as irregular in English spelling conventions.