This is a difficult thing to Google, so I thought I’d ask directly.
A long ‘i’ sound is for words such as ice, kite, like, etc.
A short ‘i’ sound is found in big, hid, spin, etc.
But what if the i is actually pronounced like an e? The example that made me think of this was lapis lazuli, where the trailing i is an ee sound.
Is that long or short, or something else?
Because the long/short vowel classification is extremely simplified for grade school. Most vowels have more than two sounds.
The IPA classification system shows them all.
Something else. The old rules that they teach in school about long and short vowels is a gross generalization (do they even still teach that?). These words have a “short” a but they are all pronounced differently:
father
pat
calm
See also International Phonetic Alphabet - Wikipedia
Long and short vowels in English is a myth.
In the outdated long/short system, that would simply be called a “long e” sound.
And according to that oversimplified classification, wouldn’t what the OP is talking about be a “long e” sound (even though the letter is an i)?
ETA: Never mind—just saw pulykamell’s post.
Hmm. I didn’t consider it was a simplification for kids. When I attempted my googling it still came up on many grammar sites like it was part of standardised rules.
I was a very cynical kid, and didn’t really like all those rules even at that age. Seemed to me there were far too many exceptions to even call them rules.
The whole long/short thing is a leftover of an idiotic attempt to forcefit English into a Latin mold. Generally speaking English does not use the long/short distinction for any phonemic distinction. There are two exceptions I am aware of and possibly a few more: rider (long) vs. writer (short) and ladder (long) vs. latter (short). I have read that English uses two dozen distinct vowel sounds and I don’t they all have names. And the rules, if any, are extremely dialect dependent. For example, I just had occasion to read something about Stan and Jan Berenstain. I imagine that for most of you, Stan and Jan rhyme. But not for me. And not for them either since they, like me, grew up in West Philadelphia. But how did I even know that the two a’s were different? I guess because the a in Stanley is different from the one in Janet. But my internal grammar knows things I don’t know.
That final ‘i’ sounds like ‘eye’, just like anno domini. And the name is Latin anyway (lapis is Latin for stone).
The distinction between long and short vowel sounds is a useful one, or at least I found it so when I was a kid. For one thing, it helps to explain how silent e works.
According to Wikipedia, dictionary.com, Miriam-Webster, and MacMillan, the final vowel is “ee”, although some of them give “eye” as an alternate pronunciation. It’s a general problem in pronouncing Latin words in English, since there are several variant pronunciation systems (Classical, Ecclesiastical, Traditional English, etc). In ancient Latin it would have been pronounced “ee”.
Never heard the final “I” in either word as “eye.”
Plus I know you’re in the U.K., but even looking up various British speaker readings of Yeats’s famous poem “Lapus LazulI,” they’ve all been pronounced with an “ee” sound. Plus within the poem, while it is not in strict rhyme, the “ee” pronunciation is strongly suggested, being paired with the word “longetivity” a couple lines down.
On this side of the water, there’s no distinction in the vowel length that I can tell in those examples. And to my ears, some Americans tend to pronounce some “t” sounds much closer to “d” than we would anyway, which would make them sound even closer to each other.
I absolutely agree about standardised rules, but generally speaking, [vowel]+[single consonant]+[e] indicates, if not a longer vowel sound, then at least a rounder one, and very different from [vowel]+[double consonant]+[e], where the vowel sounds flatter and crisper - and in other Germanic languages as well.
It’s pretty much all Americans that pronounce “t” similar to “d” in intervocalic situations like “petal” vs “pedal” and “ladder” vs “latter.” It’s not the usual “d” sound, but rather an intervocalic flap. We’ll do it in words like “eating,” “attic,” and “Saturday,” but not works like “mad” or “fifteen” or “anyday.” There’s a list of “rules” here. I put “rules” in quotes, because it’s not something that we formally learn. It’s just a feature of our accent that we pick up naturally. It sounds really weird to me when somebody enunciates a “t” in these situations but otherwise has an American accent. (I actually came across one person last week who did this with a specific word, and it was driving me nuts. I can’t remember the word, unfortunately, and it was only with that particular word she would pronounce the intervocalic “t” as a “t” rather than a flap.)
^^^^ This. I haven’t heard anyone refer to “long” and “short” vowels in decades.
IPA isn’t difficult to learn. Bit more difficult to type, I’ll admit, but so are the little bendy caps and flat caps they used to have us utilize in 2nd grade to indicate long and short vowels 
I know that different dialects pronounce things differently, but I’m trying to imagine a dialect that would pronounce a different vowel sound in “father” versus “calm” and can’t do it.
I struggle to hear the difference when some people say “father” and “bother” differently, but “father” and “calm” seem like they would be the same sound.
While the classifications themselves are outdated, I still hear people referring to both quite commonly when talking about pronunciation.
In my Great Lakes dialect, they are two distinct sounds. I imagine your dialect is probably part of the cot-caught merger. Do those two words sound the same to you? The majority of American dialects (about 60%) distinguish those two sounds. To us not in the merger, it’s the difference between an “ah” sound and an “aw” sound. But if you’re part of the merger, I imagine that description doesn’t mean anything to you.