Here is a lengthy answer to a question I get asked often: Why are some words spelled with a double letter in between and some aren't? What's up with English spelling?
First off, it sucks. I know. Everyone knows. There's a good reason for it, too. I'll get to that part, but first, let's see what going on with that e.
Let's take a look at two simple words and see if we can figure things out a bit:
'Mit' and 'Mite'
These words look similar except for the last e at the end. They also sound different. The first word has what English teachers--and not linguists--call a short 'i', while the second word has a long 'i' sound.
So here's how it works. When you have a word that has a short vowel sound, like mit, tap, or wet, and an e is added after the next consonant, the short sound becomes long. When that sound is already long, there's no need to add the e.
mit + e = mite (sounds like Mike, a man's name.)
tap + e = tape (note here how the two a sounds are very different.) This is what happens when the e is added. The vowel sound is changed into what some people hear as a "longer" sound. Got it? Okay good. Let's continue.
But let's say I need to save a short sound but I also need to add an e after the next consonant, for example, if I want the past tense of the verb tap. If I simply add the ed past-tense marker to the word tap, things get weird:
tap + ed = taped (oops! I just made the wrong word.)
English speakers--and in fact speakers of all languages--have figured a way around this problem--and many others. Before I tell you, though, you have to remember that important rule I told you earlier:
If there is a vowel before a consonant, and an e is added after that consonant, that vowel gets "lengthened."
So, what if we made sure there wasn't a vowel after the consonant, but instead there was another consonant? But which one? Should it be the same consonant always? No, that would be confusing. And weird. English is weird enough.
English speakers decided that it was best to just double the consonant in order to make sure the short sound wasn't accidentally lengthened.
Tap + ed = taped (WRONG word, Chris. You suck.)
Tap + p + ed = tapped (Yes! I'm, awesome!)
In short, the double consonant ensures the vowel isn't lengthened. But not always. There are exceptions of course.
I truly hope this post has raised more questions than it has answered. For example:
• Why aren't the sounds really short and long?
• Where did this rule come from? and how did it 'stick'?
• Chris, this rule seems to only affect words when they're written? Is this true?
• Why does English spelling, or orthography suck so much?
• What do you mean by when you said, "decided" and then put it in italics?
Yes there are lots of questions that come up when we learn. Let me quickly answer a few above:
• The sounds aren't short and long because they are actually different sounds completely, and not versions of this. A quick look at a vowel chart will show this. There is one exception, and that's the diphthong i as in the name Mike. I'd argue that that sound is longer because it is made from two vowels.
• This rule comes from the French, so blame them! Just kidding. The rule was originally introduced when the French conquered the British, an event that the British have been trying to forget for nearly a 1000 years, and one I remind them of at every opportunity. The mix of the two languages--English before this time would have sounded much more like German or Dutch than it does today--gave us what would become modern English eventually. There was, however, a great vowel shift that started around 1350, that linguists creatively called The Great Vowel Shift. Weird things happened to English then. Go read about it.
• Yep. It's true. This rule affects only the written word, because reading and writing are fake, or rather inorganic. Speaking and signing are the real language.
• English spelling, or orthography, sucks because English is the most accepting language ever! (I honestly don't know if that is true, but English is indeed accepting.) We have words from Arabic (algebra), Spanish (patio), Hindi (shampoo), Basque (chaparral), Japanese (tsunami), and literally hundreds of other languages. When English speakers hear a word they like, they borrow it and usually the spelling gets weird when different speakers form different English-speaking countries try to approximate the sounds of another language by using English letters. Remember, spelling is fake. Speaking is real. (Interesting note: Shakespeare spelled his name 29 different ways throughout his life. Spelling just wasn't standardized until printing became popular. Another insteresting note: there have been over 129 different English spellings of Libyan dictator Muammar Gaddafi in English media over the years. One in Arabic, معمر محمد أبو منيار القذافي.)
• English speakers did not get in a room and vote on how the language would be used, so I used the word decided in quotes. What happened--and I'm only guessing at this--is some people wrote words differently in the early ages of English to accomadate the different sounds. English speakers needed to find ways to show both versions of the sounds, but with only the letters English already had. They didn't add any letters, which they could have done (and should have). When people liked what they saw (remember, it's only written), they copied the people. Again, I'm just guessing at this. And by the way, there is a lot of mimicry in language. A lot.
I hope this answers your questions. If not, comment and let me know.