A German word can have several syllables that are stressed to a varying extent, usually with one syllable carrying the primary stress.
In compound words, the stressed syllable of each component remains stressed to some extent – either becoming the syllable with the primary stress or one of the syllables with a secondary stress of the compound. As the pronunciation of the vowels does only depend on whether they are stressed but not on the intensity of the stress, it is not important for the vowel quality to know which component will get the primary stress. Nonetheless, we give a short overview over the most frequent cases:
Compound verbs composed of a preposistion and a verb can have their primary stress either on the preposition (separable verb) or on the second component (inseparable verb). All verbs with ab-, an-, auf-, aus-, bei-, dar-, ein-, her-, hin-, nach-, vor-, and zu- are separable, many but not all verbs with hinter-, über-, and unter- are inseparable, and with other prepositions, both types of verbs occur.
When the first component qualifies the second, e.g. Bríeftasche which is a special kind of Tasche, the first component gets the primary stress. Most compound nouns are of this pattern.
When the two components were originally two words, e.g. Lebewóhl from Lebe wohl!, or when both components contribute equally to the to the meaning of the compound, e.g. hinwég meaning hin and weg, the second component often gets the primary stress.
In compound nouns of more than two components, the second component often gets the primary stress, especially when the first component qualifies the remainder of the compound, e.g. Oberlándesgericht. It is, however, unpredictable whether this rule applies for a given word.
The remaining portion of this section deals only with non-compound words: what is called a “word” there may either be an isolated word or one component of a compound word.
The normal rule for words of Germanic origin is that they have their stress on the word’s root, that is, the portion which remains when all prefixes and suffixes are stripped off. If the word is not entirely of Germanic origin but contains Germanic prefixes and suffixes as discussed in this paragraph, one can at least say that the stress is not on one of these. Very often, the root is monosyllabic even for quite long words, e.g. Eig-en-tüm-lich-keit-en with no less than five suffixes, none of which ever takes the primary stress. Most of the suffixes start with a vowel; for these, the border between root and suffix or between two suffixes is not a border between syllables.
For the purpose of this rule, one may regard some endings as suffixes even when they are part of the word’s root. For instance, in the word eigen, eig- has no meaning of its own so that the -en, strictly speaking, belongs to the root. The stress pattern is, however, exactly the same as if -en were a suffix attached to a root eig-, and we make no mistake when we regard it as a suffix, thus saving the labour of detemining whether it belongs to the word’s root.
Here are the prefixes and suffixes that have to be considered:
“Light” prefixes form a syllable of their own and are never stressed: be-, ge-, ent-, er-, ver-, zer-.
“Light” suffixes form a new syllable normally beginning with the consonant preceding the suffix; they, too, are never stressed: -e, -el, -em, -en, -end, -er, -es, -est, -et. The 〈e〉 often drops out when another suffix beginning with a vowel follows or when it belongs to a case or plural ending, e.g., Händlern = Händ-(e)l-er-(e)n. Of course, it can happen that the word root ends with similar patterns by coincidence. Other “light” suffixes are -ung, -nis and, less frequent, -ig and -ling for forming nouns, -in for turning a generic noun into one referring to a female, the diminutive ending -chen for nouns, and -ig and -lich for forming adjectives. By starting with a consonant, -nis, -ling, -chen, and -lich each are a syllable of their own.
“Heavy” suffixes like -bar, -los , -sam for forming adjectives and -heit, -keit, -lein, -sal, -tum for forming nouns (the last one getting an umlaut when combined with further suffixes: -tümlich, -tümer) do not take the primary stress but they get enough stress that they retain their long vowels. -schaft for nouns and -haft for adjectives have a similar intonation but are short.
When the word root, after stripping off all prefixes and suffixes, is not monosyllabic, the primary stress is not always predictable. The more frequent cases are:
Polysyllabic roots of German origin are very often stressed on the penultimate syllable. This is the reason why we could remove the light suffix of, say, eigen, even though it belongs to the root, thus leaving a monosyllabic kernel of the root which is indeed the stressed syllable. Other cases are:
If a light suffix has been stripped off which belonged to the root, i.e. which appears in all words with that root, then the syllable before this light suffix is often the stressed one, and the preceding syllable is unstressed: Wachólder, Holúnder, Kartóffel, Hornísse. But unfortunately there are quite some words of that kind that are stressed on the first syllable: Ámeise, Éidechse, Brósamen.
If, however, the entire root contains no light suffix, the primary stress is more typically on the first syllable with the second one getting more or less of secondary stress: Árbeit, Mónat (here -at is not a Latin ending), Hérzog, Éfeu.
Words with Latin and French endings (-abel, -ade, -age, -al, -and, -ant, -anz, -ar, -är, -at, -ei, -ell, -end, -ent, -enz, -esk, -ett, -eur, -ibel, -id, -ie, -ier, -ik, -ikt, -il, -ion, -ismus, -ist, -it, -itis, -iv, -or, -os, -ös, -tät, -ur) are stressed on this ending or on the first syllable thereof, leaving the preceding syllables unstressed. As an example, Denunziantentum is first freed from the Germanic endings yielding Denunziant(-en-tum), then stressed on the Latin ending: Denunziántentum[denʊnˈtsjantənˌtuːm]. For some of these endings, there are special observations:
The ending -ik is not always stressed, e.g. Genétik, Lógik, and is never stressed with the ending -er, e.g. Mathematík (in Austria Mathemátik) but Mathemátiker; when unstressed, the 〈i〉 is an open [ɪ]. -iv has sometimes only a secondary stress, especially in grammatical vocabulary (Nóminativ), and so has -or in medical vocabulary (Túmor) and also elsewhere; note the different stress for the two meanings of tenor: Tenór (highest male voice) and Ténor (general drift of a document).
The ending -ion is only one syllable and is stressed on the 〈o〉: [-joːn].
The ending -ei is partly Germanized from French -ie: it is stressed like the French original but does not take away a secondary stress from the preceding syllables, e.g. Maleréi with enough stress remaining on the 〈a〉 that it can be long.
The ending -ie exists in a stressed [-iː] and an unstressed [-iə] variant; in the latter case the stress is on the preceding syllable: Manie [mɑˈniː], Familie [fɑˈmiːliə], Zeremonie either as [tseremoˈniː] or [tsereˈmoːniə]. There is no way to tell the pronuncation of a given word ending with -ie.
The ending -ier on nouns is mostly pronounced the German way as [-iːr] (Barbier) and sometimes the French way as [-jeː] (Bankier); both variants take the stress. Again, there is no way to tell which pronunciation applies for a given word. The verb ending -ieren is always pronounced [-iːrən] with the stress on the [iː].
Words imported from other languages have often the stress pattern of the language where they originate, or the stress appears to be irregular. For instance, compare Páratyphus, Parámeter, Paraphráse. Some even change the stressed syllable: Álgebra (in Austria Algébra) but algebráisch, Algébren.
For the vowel length in a prefix or first component of a compound word not carrying the primary stress, it makes a difference whether it is regarded as an unstressed prefix or as a first component with secondary stress. While this distinction is clear for light prefixes on one hand and for autonomous first components on the other hand, opinions may be divided for prepositions. In practice, the long and close vowels of über-, vor- and zu- are pronounced close and short when unstressed; the standard has long [ʔyːbər-], short [tsu-], and varying [fo(ː)r-]. A special case is her- which is a long and close component of a compound [heːr-] when stressed but a short and open light prefix [hɛr-] when unstressed.
The simplest cause for two vowels to appear adjacent in the written form of a word is a syllable boundery between them. There are, however, several situations where the two adjacent vowels belong to the same syllable:
The second vowel lengthens the first one. In standard German, this is only the case for 〈aa〉, 〈ee〉, 〈oo〉 and for 〈ie〉 (Biene [ˈbiːnə]). In North German, thus Low German, placenames, this happens also with other vowel pairs (Grevenbroich [ˌgre:vənˈbroːx], Coesfeld [ˈkoːsfɛlt], Kevelaer [ˈke:vəˌlɑːr]).
The two vowels form a diphthong: 〈ai〉 or 〈ei〉 pronounced [ae], 〈au〉 pronounced [ao], 〈äu〉 or 〈eu〉 pronounced [ɔø]. The second vowel of each diphthong is pronounced shorter and less stressed; they are defined as close in the standard; however, open pronunciation, that is, [aɪ], [aʊ], [ɔɪ], is also quite common.
The first of the vowels is a 〈u〉 following a 〈q〉: then it is a in fact a consonant (〈qu〉 is pronounced [kv]), so that it is not part of a vowel cluster.
The two vowels serve as a surrogate for an umlaut, that is, 〈ae〉 for 〈ä〉, 〈oe〉 for 〈ö〉, or 〈ue〉 for 〈ü〉. Unless the character set of the medium misses the umlauts, this is regarded wrong spelling. Such combinations do, however, appear in proper names (Goethe [ˈgøːtə], Uelzen [ˈʔʏltsən]).
In Middle High German, the two vowels formed a diphthong which has left its traces in Swiss or Bavarian, e.g. MHG/Sw. 〈ou〉, 〈uo〉, 〈ie〉, 〈üe〉, Sw. 〈ue〉, Bav. 〈oa〉, 〈ia〉, 〈ua〉. Such old diphthongs, also with their stress on the first vowel, appear only in proper names (Lienz [ˈliɛnts], Ruedi [ˈrʊɛdi]) and in a few loanwords from Swiss German (Müesli [ˈmʏɛslɪ] = oatmeal porridge).
Particularly in the context of proper names, it is sometimes difficult to tell which case applies. For instance, compare the place names Itzehoe [ˌʔɪtsəˈhoː], Laboe [lɑˈbøː], and Buchloe [ˈbuːxloə] with three differently pronounced -oe at the end. Apart from proper names, things are usually much clearer.
In German, word roots never begin with a vowel. When they are written with a vowel at the beginning, they are pronounced with an unwritten consonant, the glottal stop [ʔ], which is used both at the beginning of a word (Arbeit [ˈʔɑːrbaet]) and within a word at the beginning of the root (bearbeiten [bəˈʔɑːrbaetən]). There is no glottal stop between two vowels in the same morpheme, e.g. Theater [teˈɑːtɛr], nor between root and ending (compare Malerei [ˌmɑːləˈrae] and Osterei [ˈʔoːstɛrˌʔae]). Some compositions are so common that they are now perceived as a single root so that the glottal stop between the morphemes is lost: vollends [ˈfɔlɛnts], reagieren [reɑˈgiːrən], but reanimieren [reʔɑniˈmiːrən] (the standard suggests no glottal stop for the first of these and an optional one for the other two).
In particular, there is no glottal stop in words like hinab or darauf: compositions of hin-, her-, vor- with -ab, -an, -auf, -ein, -aus, -unter, -über are stressed on the second component with no glottal stop between. When two vowels come together in compositions of da-, wo- with -an, -auf, -in, -aus, -unter, -über, an extra 〈r〉 is inserted so that the pronunciation without the glottal stop is facilitated. The hyphenation may today follow either the composition point (hin-ein, vor-über, dar-auf) or the spoken syllables (hi-nein, vo-rüber, da-rauf); prior to the spelling reform in the 1990ies, it had to be done the former way. As only exception, vorab is pronounced with a glottal stop: [foːrˈʔap]. (Of the words constructed as indicated above, *vorein and *vorunter do not exist.)