Just to sort it out in my own head, I’ve got to write about the usage of prior versus previous.

Prior comes from Latin for “ancient” and previous from “leading the way,” but both share roots with prae, “before.” I already know these words mean roughly the same thing: on Merriam-Webster Online, the phrases “prior to” and “previous to” refer to each other in definition. That’s how close they are. But there’s obviously a difference because they are two separate words. No matter how close they are, they have a slight inflective difference.

M-W describes previous as “going before in time or order,” and prior as “earlier in time or order.” Not very helpful: what’s the difference between “going before” and “earlier”?

The former seems to be more linear, as though it refers directly to its proximal relationship to the rest of a sequence, and places itself at the fore of that sequence. Its “leading the way” root even suggests that a previous item is placed at the head of a sequence, though that doesn’t sound right. Who would say “previously” when they mean “firstly”? But when a TV series recaps earlier events before starting the present episode, a voiceover may announce, “Previously on [insert show here].” In effect, they’re saying, “What you’re seeing now happened first, to get you ready for what you’ll see tonight.” It’s not at all common for the announcer to say, “Prior to tonight’s episode…” By contrast, “earlier” simply sounds like a moment in time whose only defining characteristic is that it happened before the present. There’s no implication as to whether it comes before or after any other earlier events: it is only before right now.

Interesting are the secondary meanings to each word. Both words cite preceding as a synonym, but the second definition for previous is “acting too soon,” and prior’s is “taking precedence (as in importance).” Interesting, right? Previous means being a little hasty, acting without having all the information, and prior is a hierarchical establishment, and we may even get the word priority in mind when dwelling on this. Can these secondary meanings shed any light on usage?

When writing a résumé, one is faced with “prior to my work as” versus “previous to this position,” &c. Or is it “previous to my work as” and “prior to this position”? Say them aloud long enough and you may confuse yourself—it’s certainly a point to confound the ESL speaker. And actually I found this discussion on a message board, where someone learning English asked for the difference between these two words and no native English-speaker could produce a cogent or definitive response.  Embarrassing!

So let’s look at what we know of the words. Say you worked at a fast-food joint, then as a data entrant, and finally as an administrative assistant. If you wanted to talk about your ignoble beginning, which word would you use:

1. “leading the way” / “acting prematurely”
2. “ancient” / “taking precedence”

What a terrible couple of choices. Just looking at those definitions, I would probably choose #1 to describe the first job on my résumé: “Previously I worked as a short-order cook and a data entrant.” Yes, I would definitely use previous if I were going to rattle off my past jobs in chronological order. If I were simply hearkening to past experiences without order, I might say, “Prior to this I’ve been a customs inspector, a lifeguard, a parking lot attendant, and a transcriptionist.”

That’s the best I can come up with, so that’s how I’ll use them until someone brings a larger hammer down.