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As we know, the English language doesn't have the /x/ phoneme anymore (at least in an everyday kind of context*) and the sound seems to have been dropped in many words, such as in light or eight.

However, consider the following words: laugh, tough, rough and cough. It strikes me as very odd that what was once a /x/ would turn into /f/; it seems much more likely to me that it would have shifted to /h/, /ʃ/ or even /g/ — but definitely not to a fricative at the front.

My question is: Has it been attested that /x/ shifted to /f/ in certain situations ? Is there an explanation for this phenomenon?

laugh is lachen in both German and Dutch with a /x/-like sound; rough is ruig in Dutch and ruuch in Swiss German (both with /x/). So there is some relation between /x/ and /f/, but it perplexes me.

(On an irrelevant note, I also notice that shaft is Schacht in German, but the whole ft vs. cht at the end of words seems to be more complicated and possibly independent from the /f/ in the words I mentioned in the second paragraph. There are some Dutch-German pairs where they systematically differ: {kracht, Kraft}, {lucht, Luft}, {stichting, Stiftung}. This is odd, too, but not in the scope of this question — or of this site for that matter.)

* disregarding all annoyed teenagers who use "ugh" excessively ;)

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Are you certain that those words used to use /x/ ? That isn't at all clear to me. –  Rory Alsop Jul 18 '14 at 14:09
@RoryAlsop rough comes from Old English ruh which was pronounced /ruːx/. Can't find definitive evidence for laugh or cough. The word had hh in Old English and gh in Middle English from what I looked up. I don't know how they're pronounced, though. I just know the words I mentioned have cognates with /x/ and there seems to be some pattern. –  ljacqu Jul 18 '14 at 14:14
/x/ to /f/ is a shift from velar to labial which requires very little practical change (start with a continuous /x/ sound and bring the lower lip closer to your upper teeth). this has some more info (note that in some languages/cases the shift goes the other way round) –  msam Jul 18 '14 at 14:51
Native speakers of different languages hear different phonemes as close to each other. For example, a German speaker once asked me why English-speaking people replace /x/ with /k/ (consider loch and Bach), since they sound nothing like each other. The best answer I could give him was that they sounded similar to English speakers, which didn't satisfy him at all. Presumably, /f/ was the closest-sounding phoneme to /x/ for English speakers when this change happened in Middle English. –  Peter Shor Jul 18 '14 at 15:05
Och, I think it's just sassenachs who've lost their /x/ –  High Performance Mark Jul 18 '14 at 16:12

1 Answer 1

up vote 9 down vote accepted

Not really answering "why" but here is "how":

This is called labial-velar shift and occurs in many other instances. Both /x/ and /f/ are fricatives and the change required to go from the velar /x/ to the labial /f/ or the other way round is pretty small (to make an /f/ start with an /x/ and touch lower lip to the upper teeth for, alternatively make an /f/ and open your mouth, you should end up with an /x/ ).

old english/old high german ruh -> english rough / german rau(this changed in a different manner in the case of german)

old english/old high german hlahhan -> english laugh / german lachen

it can also occur the other way round:

old high german luft -> dutch lucht

Much more detailed information can be found in this paper (as well as, I'm sure, other sources)

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Interestingly, in Swiss German we still say ruuch for High German rau (English rough). –  ljacqu Jul 19 '14 at 5:23

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