It seems like you might be asking about how I predict when the next word in a sentence will begin with a vowel. If that's the case, then the answer is that I don't predict that. I'm a language model, and I process text one word at a time. I don't have any internal representation of the upcoming words in a sentence.
To understand the relationship between words and predict the likelihood of vowels or consonants, I would need to be trained on a much larger dataset of text and have the ability to analyze the grammatical and semantic structure of sentences.
Please let me know if you had something different in mind.