What decisions do English speakers make subconsciously?

Thorn begins with the voiceless th sound – at least that’s the way I hear it pronounced.

“Thorn” begins with an unvoiced “th” sound (as do “thin,” “thistle,” “theater,” etc.). “This” and “that” begin with a voiced “th” sound.

I can’t think of a counterexample to this rule, but I don’t know why it should be that way.

I thought I was saying all of those with the same “th” sound; but you’re right, there is a difference.

But there’s a bigger difference in the way I say the unvoiced “th” at the end of “with”.

Note also that there are not that many words where it is final either.

That’s interesting because there has to be a reason for this phenomenon. The unvoiced and voiced “th” are distinct phonemes in English [θ, ð], not allophones but their almost complementary distribution seems suggestive of… something.

Japanese doesn’t have articles, either.

In Arabic, there are definite articles, but not indefinite articles.

Thither

Not common, but not sure if it’s considered obsolete. Sing it every year at Xmas.

It does sound odd on the ear.

Thither isn’t an exception - it’s an example of a function word that begins with voiced th, like this, them, there, thou, then, than…

The exceptionless rule is that content words can’t have that sound in word-initial position.

That’s an interesting question. I found a Wikipedia page that gives estimates between 25% and 33% of words being native to English.

Foreign-language influences in English - Wikipedia

However, because the more commonly used words are statistically more likely to be native, and more specialised words more likely to be borrowed, the proportion of spoken English that is made up of native words is much higher - maybe 80%.

Wikipedia has a list of words native to English:
List of English words of Anglo-Saxon origin - Wikipedia
(although some entries are hybrid between native and borrowed: “infrared”, “biofeedback”)

Scanning down through the list, I am tempted to propose a stronger statement:
All native words without a prefix are stressed on the first syllable
AND
All native words that begin with a prefix that is not itself a content word are stressed on the first syllable after the prefix

Ha, yes, here’s that bit on Conan, very funny:

Off the top of my head, all I can think of is “lathe”.

That doesn’t seem as odd as the start-of-word one, though. Plenty of languages have rules about sounds or combinations of sounds that simply aren’t allowed in certain positions of a word, like the beginning or the end. Other examples in English include “ts” or “mb” at the beginning of a word, even though other languages have no problems with those. What’s odd about the voiced-th-rule, though, is that it clearly isn’t completely taboo in English, as evidenced by all of the function words (including some very common ones like “the”, “this”, and “they”) that do start with a voiced th. Clearly, that sound at the beginning of a word doesn’t cause any phonetic difficulty for English speakers. It’s not alien to us. And yet the rule still holds absolutely.

I don’t think it’s that simple-- There are some words that change their stress to change their part of speech, like “record” and “entrance”. Though, so far as I can tell, those words all include a prefix, so they’re not an exception to the first rule.

Bathe, soothe, writhe, smooth…

Threre are indeed some examples of final [ð] in English, but they are relatively rare.

That’s what I was trying to get at.

There seems to be some restrictions on the use of [ð] in the initial position and it looks as if they are semantically motivated for some obscure reason.

Smother? Mother? Father? Bother? Brother? I gather there are plenty…

All of those end with r. Words ending in r are a dime a dozen.

The discussion was about words with a final voiced th sound.

Oops. I should just take a deep breath and breathe.

The pattern (except 'smooth") seems to be a “-the” ending?

The use of do/does in questions has been mentioned briefly upthread:

Where you got that?

Where did you get that?

You might think the rule is that an auxiliary verb (do, will, have, be, etc.) must be used:

Will you tell me where you got that?

Have you been shopping?

Are you going to tell me?

But sometimes it’s not necessary:

Who did give you that?

Who gave you that?

The rule or its exception, then, is that an auxiliary verb isn’t necessary when asking about the identity of the subject.

And, of course, fluent speakers don’t have to think about that and get it right every time.

Poor English students!

There aren’t a ton of them so it may be hard to discern a rule with an exception from some other kind of rule. But there are more that don’t have an e on the end. I thinkore of the ones without the e are in an in-between state, where they can be pronounced either way, like “with.”

Some others: loath (and loathe), mouth (as a verb), betroth.

The sound of th is voiced if it’s between voiced consonants or vowel sounds (which are always voiced). I have a hunch that the words ending in a voiced th sound are primarily adjectives and transitive verbs, so they are almost always followed by another word, or have an ending added. There’s probably a History of English podcast on this. I know I heard one about other voiced and unvoiced consonants.

I also read somewhere, but can’t immediately find it again, that Old English did not have the voiced th sound, so it’s probably not that surprising that there are few native English words that start with that sound.

I suspect that there was some other sound, like d, or t (or both) that got replaced with the voiced th in the middle of some words, once it came into the language.

But it is very surprising that the few words that have it are part of the absolute core of the vocabulary.

Yes, and such a specific group. I’m sure there’s a reason for that, but I don’t know it.