Sources of lexicon phonological inventory changes in consonants changes in vowels long consonants allophone of /g/ ic --> I	unrounding of /y/ instrusive b, d, t "k" distributed for "c" /mb/ --> /m/ diphthong smoothing epenthetic schwa long/short vowels	plain adverb allographs u --> o (e.g., "son") thorn --> th loss of inflection role of prepositions prosody
grammatical gender strong verbs weak verbs perfective levelling shall/will infinitive	passive infinitive negatives ngative contractions synthetic vs. analytic

 
ISSUES:

1. Reason for increase in phonemic inventory
2. Quantitative distinction between long and short vowels
3. Weakening of strong verbs
4. Reasons for the loss of inflections