Separated by a Common Language

Ben Yagoda (Friend of SbaCL and Not One-Off Britishisms blogger), who had recently noticed a US journalist saying learnt instead of learned, asked whether I'd covered the ‑ed/‑t alternation. It's one of those things that I've been putting off for a long time because it would be a very long post. Now I've been shamed out of my laziness.

In order to do this in any kind of sensible way, I feel like I need to explain some things about the past tense in English. I'll try to introduce terms gently, with links to sites with deeper explanations. At points I will be a bit sloppy and use more familiar (and less precise) terms (like past-tense). And I'm going to be very sloppy about phonetic spelling, both because not everyone knows the International Phonetic Alphabet (IPA) and because if I tried to use the IPA we'd have to get into not-especially-relevant differences in pronunciation of many of these words. 

The origins of ‑ed

Let's start by thinking a bit more about ‑ed. Old English had different categories of verbs that were put into past tense (preterite) in various ways. The so-called strong verbs were those that changed their internal vowel. Some of those are still 'strong' in Modern English, like drink/drank and write/wrote. 

Those that ended with the (then multiple) suffixes that would eventually become ‑ed are weak verbs. They don't undergo an internal change to make past tense; a suffix is just stuck on the end.

Nowadays, we think of strong verbs as "irregular verbs" and ‑ed verbs as "regular" verbs, but back in Old English the verbs that we now think of as "irregular" fell into regular patterns in a more complex system. 

For centuries, English has been bending toward verb weakness. Many Old English "strong" verbs are now made past-tense with ‑ed, like starved (rather than something like storve) and baked (not boke). 

But ‑ed is only the spelling of the past-tense suffix

That is, each of these past tense forms is pronounced with one syllable. The ‑ed does not represent a vowel+consonant combination. Buzzed isn't "buzz-ed", it's "buzzd". 

If you don't hear the difference between those, think about learned in these two contexts:

I learned a fact versus a learned scholar 

The first has one syllable ("lernd"), the second as two distinct syllables with a distinct vowel in the ‑ed. That two-syllable learnéd (sometimes spelled/spelt with the accent mark) is a special case; it's an adjective, rather than a verb. We're going to stick to verbs, not adjectives in this post, but that adjective is handy for illustrating what we're not doing in words like buzzed. We're not pronouncing a vowel in ‑ed.

Some other ‑ed verbs do have a pronounced vowel in ‑ed:

• tasted, boarded, dated, padded, minded: each has two syllables.

If you start from the spelling, you might think that buzzed is buzz+ed and the E has got(ten) lost. But language doesn't start from spelling, it starts from sounds. Instead of the suffix being ‑ed, with some weird places where the vowel is dropped, it makes more linguistic sense to see the suffix as ‑d and to observe that we have rules for what to do when that [d] rubs up against other sounds in pronunciation. The rules are:

• The [voiced] -d becomes [voiceless] ‑t when it follows a voiceless consonant sound. (We say it assimilates to voicelessness. Assimilation makes things easier to say quickly.)
• A vowel is inserted (epenthesized) when we try to attach the suffix ‑d to a /t/ or a /d/ sound. These consonants are pronounced by tapping the gum ridge behind the teeth with the tip of your tongue (they're alveolar plosives). and if we tried to pronounce them together, you'd not be able to hear them both. (In English, we would pronounce padd the same as pad.) So, inserting the vowel makes the doubled alveolar consonants pronounceable for the speaker and hearable for the listener. 
• In all other cases, the suffix remains ‑d in pronunciation.

final d > t (no vowel change)

-pt versus -ped with vowel change

So, I was right that there's more -rnt in the perfect than in the preterite, but it's a smaller gap than I'd thought I'd find. 

-led versus -lt

Finally, the Ls, one of which you've seen already in this post: spelled/spelt.

These fall into two categories, with and without vowel change. 

The vowel-changing ones are solidly in the "irregular" category, with a bit of movement in the rarest of those, kneel>knelt.

With vowel change	Past form	AmE %	BrE %
deal	dealt	100	100
feel	felt	100	100
kneel	knelt	85	89

We see some of the biggest differences between AmE and BrE in the non-vowel-changing ones—with some caveats about homonyms below.

Without vowel change	Past form	AmE %	BrE %
build	built	100	100
dwell	dwelt	86	83
smell	smelt	13	48*
spell	spelt	7	49†
spill	spilt	11	38^
spoil	spoilt	5	51

*Smelt is a bit tricky because it can be a verb in its own right (smelting metal) and it's also a fish that's eaten in North America. The corpus, however, is bad at distinguishing these things. The majority of smelts in the results reported here are the past tense of smell, but it would be too much work to tell you exactly how many.

smelt!

†Spelt is another problem one because it is the name of a grain. I tried sorting out the noun uses from teh verb ones, but it turns out that most of the ones tagged as "noun" in the corpus are, in fact, instances of the verb. So the numbers here include all spelts. 

^In the case of spilt, I wondered how much adjectival use mattered, particularly in the phrase "cry over spilled/spilt milk".  So, I searched for "spilled/spilt milk" and found that Americans are pretty evenly split on spilled versus spilt in the phrase (36 hits vs 32), whereas in British English it was 76 versus 18 hits. Those spilt milks account for 14–18% of the spilt percentages above (which is to say, that phrase isn't adding much to the AmE/BrE difference).

miscellaneous irregulars 

There are a few more irregulars-ending-in-t; these ones end in fricative sounds. But it's not worth saying much about them, since they're much the same in British and American English.

leave>left: Everyone uses the irregular for this one. Where leaved happens, it has to do with leaves (like on a tree or a table), not leaving.  

vex>vext: The -t version is still playable in Scrabble, but the corpus tells us no one's using it in UK or US. I'm not even bothering to look for other verbs ending in x. 

dress>drest: No one's using this one either! But...

bless>blest: We find a bit more of this one, since old-fashioned spellings are common in religious language, either because they're quoted from long-ago translated scripture or because they're styled to sound like scripture. Still, only 2% of the AmE "past" forms are blest and only 1% of the BrE.  (I say "past" because a lot of them are probably adjectives.)

The moral of the story is...

While some -t spellings are more common in current BrE than in current AmE, it would be wrong to call them "the British spelling", with one exception: leant.  There we have clear evidence of a transatlantic divide where the -t version is the firm majority in the UK and the -ed version is much preferred in the US. 

In the other cases, there may be more preference for one or the other in US or UK, but the same forms have the majority/minority in both countries (at least in this corpus, which was collected 12 years ago). That is to say, you're much more likely to see spelt from a British writer than an American one, but an awful lot of British writers are writing spelled. Learnt will tell you that a document is almost certainly not American, but learned will not tell you that the writer isn't British—and so forth.