Definition: Given the Question and Answer pair, detect whether the answer is acceptable or not. Denote acceptable answer as "yes", otherwise denote as "no". An acceptable answer is consistent with the context in question, detailed, long, and uses general knowledge of English. Answers that are not definite and suggest a variety of options are not acceptable answers.
Input: Question: is it 'a usual' or 'an usual'? 'A usual' sounds more correct in my head ('Today was a usual day.') than 'an usual', but u is a vowel. Which one is correct and why? 
Answer: The technical definitions are: open vowel sounds or closed vowel sounds. All open vowel sounds such as, orange, envelope and image require the article "an" to bridge the two open sounds. Closed vowel sounds typically start with an unwritten "yu" consonant such as "a university" or "a united Europe, a Europe which is united" and therefore use the more common "a" article.

no