This was originally published in my work Slack on 2016-10-18, but I’ve since been convinced that more people than just those few who can even read it there might be interested. I’ve edited it for clarity and correctness. I’m going to migrate all my Linguistics Minutes over to my blog and probably post future ones here.

This one also requires a little foreword for those who don’t work with me. Below, there are some initialisms that aren’t defined. They aren’t super important to understanding the post, but if you’re curious, “MMF” stands for MapMyFitness, a product my part of Under Armour works on and “UACF” stands for Under Armour Connected Fitness, which was the name of my part of Under Armour at the time of this writing.

This one’s a reader request (even I didn’t know I took requests 😜):

I want to know why we type out “an MMF user” but “a UACF user” when they taught us otherwise in school.

When you were in school, you were probably taught that we “use a in front of words starting with a consonant and an in front of words starting with a vowel.” Here’s a thing about English teachers, though: They love to tell you about rules you should be following, but that’s not really how language works. They’re also charged with getting those rules to stick in the minds of distracted, uninsterested 7-year-olds, so they simplify things greatly and often.

Do you know what the vowels of the English language are? You might think they’re “a”, “e”, “i”, “o”, “u” (and sometimes “y”). This is the list we’re often taught as kids. Those, however, are letters. Vowels, on the other hand, are sounds. English has way more than five vowel sounds and they show up in a lot of different places. Similarly, consonants aren’t letters, but sounds.

Before we look at some examples, let’s talk about why we have two different forms of this word. A/an is what’s called an “indefinite article” in Linguistics jargon (the is the “definite article”). It appears routinely in a lot of different phonetic environments and is very closely tied, semantically, with the word that follows (because word order is so important in English, it always preceeds the nouns it applies to).

Because of this close association and commonality, it’s important to be easy to say (or, rather, it is said so often that it naturally changed to become easy, since people are lazy). Saying two vowel sounds in a row is sort of hard. You either end up mooshing them together into a diphthong, dropping one or adding some kind of consonant. Depending on which sounds predeed or follow a constonant, some are harder to say than others, but /n/ has the nice property of being kind of in the middle of the mouth, voiced (so it plays well next to vowels) and sonorant (you can say it for a long time, if you like). This makes is a particularly alluring consonant to slip in there. It’s basically lubricant between vowel sounds.

Oll korrect. Examples, right? Just… one more thing. Since I’m going to be talking about sounds, I’m going to trot out the International Phonetic Alphabet (the IPA). It’s an alphabet invented by linguists to accurately describe the sounds humans make when speaking instead of relying on the spelling native to the language. You can read more about the IPA on Wikipedia, if you like.

I’m not going to use it to the full extent that’s possible, since it can get pretty hairy, but in a mode that’s meant to describe the general idea of a sound, rather than the specific sound made by a speaker in a particular utterance. The notation for this is to enclose the characters in slashes. For instance, my first name might be transcribed as /bɛn/.

So. Take the word umbrella. Most English speakers pronounce this word something like /umbɹɜlə/ and would probably construct “an umbrella”. This is not because the word is spelled starting with “u”, but because the word sounds starting with /u/.

However, the word in the title of this post, urologist, also starts with “u”, but most folks pronounce it something like /jəɹɑləd͡ʒəst/ (we use a lot of /ə/ in English, almost exclusively in unstressed syllables). The /j/ is a consonant sound that is mostly spelled “y” in English (e.g. yes is /jɛs/), so even though it’s not spelled explicitly in this word and it looks like it starts with a vowel, this word actually starts with a consonant.

This brings us to the specific words in question: MMF and UACF. These words are abbreviations, which means the spelling is often very divorced from the pronunciation since you’re meant to say the letter names, not make the letter sounds (as opposed to acronyms, where you are meant to pronounce the sounds e.g. SCUBA). So MMF is /ɛm ɛm ɛf/ and UACF is /jʊ ɛj si ɛf/. When you look at the IPA notation for those words, you start to see that even though MMF starts with the letter “M”, it starts with the vowel sound /ɛ/ and while UACF starts with the letter “U”, it starts with the consonant sound /j/.

So that’s the deal: It’s about sounds, not letters. And when you’re speaking, you probably hardly ever think about it.

Interesting side note, when we are focusing on a and an in speech, we often pronounce them like /ɛj/ and /æn/, but in normal speech, because they’re not words that contribute to the core meaning of a sentence, they usually get minimized to /ə/ and /ən/.