During the Eye of Magnus quest, http://www.uesp.net/wiki/Skyrim:Mirabelle_Ervine says this about the Synod, "Mages based out of Cyrodiil. They fancy themselves the Imperial Authority on magic these last few hundred years."

Didn't she mean couple hundred years? Was that an error on Bethesda's part? Or is Mirabelle supposed to be absent minded just during that brief second?

Don't the terms mean essentially the same thing? The way I read it, "a few" is simply a less specific form of saying "a couple."

I think you might be reading it too literally.

She never said they were around for 300 years.

You're just assuming they were.

Just read what you wrote again. She's saying that the mages from Cyrodiil (i.e the Mages Guild and its successors) consider themselves the authority. Not specifically the Synod, who are a section that split from the earlier guild. The College of Winterhold was independent of the Mages Guild as far back as anyone can remember.

The period between TES IV and V was a lot longer in in-game years than we tend to realise - two hundred years is a long time for in-game humans; the Mage's Guild is beyond a distant memory, and as far as Mirabelle's concerned, the Synod and College of Whispers are probably the only relevant groups in Cyrodiil. It's perfectly reasonable for her just to say 'a few hundred' rather than a precise number.

I think she means cyrodillic authority on magic in general. Couple means two. Few means three or more. I know it could easily be laziness or a mistake, but I like to interpret it that way.

No. It does not. The definition of "few" is a small number: http://www.merriam-webster.com/dictionary/few

"A couple" and "a few" tend to be used interchangeably anyways. Saying "a couple" for more that two things might be incorrect, depending on how you look at it, but "a few" for two things isn't.

Either way, the Synod/College of Whispers might not have been around for even 200 years. When was the exact date that they were established again?

Wow, ok. Never even realised that! And I'm an English tutor... Thanks for clearing that up for me.

That may be popular if you're talking about slang, but couple has always meant two. (I hope anyway, wouldn't it be awkward if I got both wrong? ) Anyway, back to the topic.