Lecture indo-European Family of languages English as a Germanic Language

VI. Proto-Germanic Phonology
6a. The accent on a syllable depended partly on stress (acoustic loudness), partly on intonation (musical pitch), but some languages relied more on stress than on intonation.
PIE probably made great use of free (i.e. could fall either on the root syllable, or on the suffix, or on the inflexion) accent, but in PG the stress accent starts to become predominant. At the same time, there was a strong tendency in PG to adopt a uniform position for the stress on a word by putting it on the 1^st syllable, except verbs (at the time when the stress became fixed a syntactic combination of prepositional adverb with the verb was not yet a single word, so such combination developed into compound words with the second element stressed). The role of the dynamic stress grew. It meant that in PG there existed more stressed and less stressed syllables.
The tendency to stabilize the accent on the first syllable together with the adoption of a stress type of accent had profound consequences: it all led to a weakening and loss of unstressed syllables, especially at the end of the word. This trend continued in Germanic languages throughout their history (ex. OE beran > ME bere, ber > ModE bear).


6b. 1. The phoneme system was reconstructed by some 19^th century scholars, who claimed that in PIE there was a rich amount of stop consonants. In PG this system underwent great changes. The most important series of changes is called “the 1^st consonant shift” or “Grimm’s law” (after Jacob Grimm, 19^th cent. philologist).
The consonant shift is meant by the complex of phonetic processes, the essence of which is the change of the type of articulation of IE voiced stops (with the simultaneous retaining of the place of articulation). The shift is considered to have started some centuries B.C and finished (approx.) in the 5^th-6^th cent. A.D.
Modern Germanic linguistics states that the 1^st Consonant Shift includes several changes within a definite group of consonants.