Is there a rule for realizing a-schwa before vowels as [r] at words boundaries?

Question

I know that Standard German pronunciation is strictly governed by rules, i.e. the pronunciation of originally German words are to a large extent predicted. However, I don't know whether there is a general rule for realizing a-schwa before vowels as [r] when it occurs at words boundaries.

Examples of [r]:

hieraus, vorauf, voran, hierauf but not hier auf dem Tisch

Examples of [ɐ]:

überall, überaus, allerorts, Vorabend, Lehrerassistent

I can make my own rules to fit the real pronunciatioin such as compound words vs. separate words or prepositions vs. content words and so on, but I can't see the difference between voraus and überaus for example? Is there a rule or should I always learn the pronunciation of each word separately?

Answer 1

Phonetics/Phonology is not really my area of research, so someone else may be better equipped to respond, but it appears to me that this has to do with the boundaries of the (phonetic) syllables. If you look at hieraus, voran, hierauf, their common feature is that the r sticks to the preposition: hie|raus, vo|ran, hie|rauf. Unlike in your second group of examples, the word boundary is not the same as the syllabic boundary. Looking this up, this seems to be a pattern with specific prefixes. E.g., Wiese, The Phonology of German, 1996, 66, notes that

Prefixes in general constitute their own, separate domain of syllabification. There are two well-defined sets of exceptions. The prefixes her+, hin+, and vor+ in combination with prepositions (her+an, hin+aus, vor+an) are syllabified so that their final consonant is onset to the second syllable [...] The other exception is the suffix in-, which assimilates to following consonants as in illegal, irregulär, impotent.

Answer 2

One possible rule:

1. If we have two combined prepositions, r sticks to the next preposition (vo|rauf, vo|ran).

2. If we have a preposition combined with other word classes e.g., nouns, adverbs, verbs… etc., r sticks to the preposition and pronounced accordingly (für|einander, hie|raus).

3. If we do not have a preposition, a-schwa is still pronounced a-schwa (aller|orts, Lehrer|assistent).

Two exceptions: herein and vorüber pronounced with r.

In order to give a precise answer, I had to do a systematic search of all possible combinations of a compound adverb which is obviously the main culprit here. In the following I will provide some examples for each possible combination (some of them do not involve a-schwa but mentioned to clear the issue more):

1. Adverb + Adverb (total 233 results): achteraus, herein, hierorts, hintenheraus, obenherein, obenherum.

2. Adverb + Preposition (total 95 results): herab, heraus, heran, herauf, herüber, herum, herunter, hieran, hierauf, hierunter, hierin, hieraus.

3. Preposition + Adverb (total 41 results): überaus, vorab, überübermorgen, vorerst, vorüber.

4. Preposition + Preposition (total 13 results): voran, voraus, vorauf.

5. Preposition + Pronoun (total 33 results): füreinander, hintereinander, überall, übereinander, untereinander, voreinander, widereinander.

6. Noun + Adverb (total 72 results): bergab, bergan, kopfvor, jahraus, jahrein, türaus, türein.

7. Adjective + Adverb (total 78 results): geradeaus, hochauf, kurzum, querab, querüber, weitaus.

The big idea here lies in word formation. Some words can be a preposition and an adverb e.g., ab, aus, vor, über… etc. The same word is a preposition in some words but an adverb in others sometimes in an unexpected way.

Example 1: aus is a preposition in heraus, hieraus, voraus but an adverb in überaus, achteraus, jahraus, weitaus.

Example 2: ab is a preposition in herab but an adverb in vorab.

Example 3: über is a preposition in überaus, überall, herüber but an adverb in vorüber and querüber.

Example 4: Vor is a preposition in voran, voraus, vorauf, vorerst, vorüber but an adverb in kopfvor.

Note 1: I did not look for all possible combinations of words other than compound adverbs such as compound nouns or adjectives. but I will assume that this rule applies unless counterexamples are provided.

Note 2: In my search, I used canoo to get these possible combinations and dict.cc to check the pronunciation.

Answer 3

What a puzzling question! What is an "a-schwa"? Should we read "... a general rule for realizing a schwa before consonants as [r]". And even if, where would these schwa's be in the following examples?

hieraus, vorauf, voran don't have schwa's. hier in hier auf dem Tisch has one: /hi:ə/, but what does /hi:ə/ have in common with vorauf /for'auf/ ?

überall, überaus, allerorts, Vorabend, Lehrer, Assistent do have a schwa: /y:bə/, /ɑlə/, /a:bnt/, sometimes /a:bənt/ etc.- but what do these examples and their schwa's have to do with the previous examples?

Is it possible that you have not yet understood that a schwa is this one: /ə/, and only this one?

Take a look at the Vokaltrapez on https://de.wikipedia.org/wiki/Vokaltrapez. The only phoneme that was given the name 'schwa' is the ə right in the middle.

You might want to reconsider your problem and your question(s). :-))

Cheers!