According to mario pei, slang is common to english as well as to foreign languages (80). many words that were once considered slang are now words of full, legitimate standing in our language. some of these words are strenuous, spurious, clumsy, and bogus. even shakespeare introduced into current usage such slang terms of his day as hubbub, fireworks, fretful, (to) bump, and (to) dwindle. pei estimates that about 90 percent of all slang words eventually become permanent (johns 12).
what is the author's style?
he is using slang
he is using a very formal style
he is using a very informal style
he is using critical style

The correct answer is B. He is using a very formal style

Explanation:

In writing, the style refers to the particular way in which a writer conveys a certain message that is determined by the words the writer uses. In the case of formal style, in this style, certain elements such as conventions of language and grammar, technical or complex words prevail while slangs, colloquial words or too informal words are avoided. This type of style can be identified in the text presented because the author of it avoid colloquial term or word and instead uses complex terms such as "legitimate standing in our language" or "Pei estimates that about 90 percent". Therefore, in this case, the style can be mainly described as a very formal style.

in june, we will have been married for eighteen months. (i am assuming this is what you want? the sentence, as you have presented it, is grammatically incorrect--   you want it corrected, yes? )