"a" or "an" ubiquitous? [duplicate]

I am unsure whether to use "a" or "an" in the following sentence:

Video games have become a/an ubiquitous part of American culture.

For me, saying the two sentences out loud makes "an" seem like the right choice but Microsoft Word proofing disagrees.

Solution 1:

This isn't straightforward. In my version of English, I would say 'a ubiquitous'. It seems that the grammar checkers in MS Word agree -- both in US and UK English.

However, take a look at this ngram of published works.

Google ngram: a ubiquitous,an ubiquitous

You can see that a changeover occurred in the late 1880s but both versions survive up to the present day.