###INSTRUCTION: Fix grammatical mistakes in this sentence: The sound/q/has a very low frequency of occurrence that could be limited throughout a few noun, such for (al-Qur'an), " the holy books " and (al-qahira), " Cairo ".
###RESPONSE: 
The sound/q/has a very low frequency of occurrence that can be limited to a few nouns, such as (al-Qur'an), " the holy book " and (al-qahira), " Cairo. "
The sound/q/ has a very low frequency of occurrence that can be limited throughout a few nouns, such as (Al-Qur'an), "the holy books" and (al-Qur'an), "Cairo."