When is “sch” spoken like “sh” and when like “s” “ch”?

Question

Regarding the words like Hose, Dose, Rose the pronunciation of the diminutive (Höschen, Döschen, Röschen) is with an explicit "s" phoneme. Opposite to the usual "sch" pronunciation.

Is this a rule? (applies to all diminutives created from s) Or are there other examples?

Answer 1

s and ch are spoken separately, if (and almost only if, see below) they are meeting due to some sort of word composition. The diminutive forms you give are examples for this: For instance, in Höschen is a composite of the “umlauted” stem of Hose, i.e., Hös-, and the diminutive suffix -chen. Something similar can happen with regular word composition, like in Universitätschor (university choir). It’s essentially the same reason as to why s and h are spoken separately in the English mishap.

If you are unsure about a word, you can take a look at the hyphenation: s and ch are spoken separately if and only if your dictionary allows hyphenating the word in-between the two.

Some sidenotes on this:

• In proper names, this can actually cause some confusion even to native speakers. A rather prominent example is the Röschenhof. Also, I once met somebody whose last name was Höschen with sch spoken like the English sh.
• Additional exceptions are some loanwords, for example Eschatologie and Ischias, whose s and ch are to be spoken separately. However, one could argue whether this is still the only correct way, as even most native speakers “mispronounce” these words.
• In old German orthographies (mostly blackletter) which used the long s (ſ) in addition to the round s (s), you could actually distinguish those cases from spelling: If s and ch were spoken separately, they were spelt sch, otherwise it was ſch. For example, you would have spelt Döschen, Röschen, Univerſitätschor, Ischias but Wäſche, ſchreien, Buſch, Röſchenhof.

Answer 2

There is no productive phonetic rule in High German which merges /s/ + /ç/ → /ʃ/ or /s/ + /x/ → /ʃ/, so the pronunciation of the trigraph ‘sch’ always [*] depends on the pronunciation of the components – and when there are no components, it should be a /ʃ/.

Historically, though, there was a merger for at least /s/ + /k/ → /ʃ/ or /s/ + /x/ → /ʃ/ which is evidenced by Old High German scrîban (High German schreiben, to write, cf. Swedish skriva). (See also Wikipedia: http://de.wikipedia.org/wiki/Sch_(Trigraph))

[*]: As has been mentioned, there are exceptions for loanwords, which – possibly under the influence of their spelling – have changed their pronunciation to /ʃ/; and on the other hand, there are folk etymological re-interpretations for the pronunciation of the ‘sch’ in the Röschenhof. Lacking more examples, I don’t think this is a productive rule.

Answer 3

When creating a "sch" with a diminutive, it is always an explicit "s" phoneme.

This is because the pronunciation depends on the pronunciation of the original word.

Answer 4

It's regional. High German is merely the local dialect from one of the German regions. Outside that region, some of the others pronounce "sch" as "sk", others as "sh".

Answer 5

sch is always spoken as /sh/. There is one exception. When you add the diminutive-suffix -chen to nouns ending in s. Haus Häuschen, Maus Mäuschen. In such words the original s does not change to /sh/, otherwise you would have no idea of the original noun.