An appositive can be only a noun that is used to explain another noun that came before, and also it can be a complete noun phrase, which is used for the same purpose. <em>In the sentence presented, the noun phrase "a brilliant poet" provides information about the noun "John Milton", but this information is not necessary for the meaning of the sentence, it's only an additional description.</em>
The entire question is bold, bit I am assuming it is tasting. So I would say past. I don't know for sure, so let me know if I am right. Sorry, if it is not.
