Midterm Study Problems

Answers to Midterm Study Problems
【中略】
Problem 2.5 Farsi
There are three sounds here, which I represent as follows:
[R*] voiceless trill
[D] voiced flap
[R] voiced trill
There are no minimal pairs (or triplets) in the data. In fact, the three sounds are in complementary distribution, as follows.
[R*] occurs at the ends of words;
[D] occurs between vowels;
[R] occurs elsewhere (at the beginnings of words, after a vowel and before a consonant, after a consonant and before a vowel).
Thus, they are all allophones of a single phoneme.
The basic allophone is the voiced trill, [R]. This is because the phonetic environments in which it occurs cannot be described as a natural class. It would therefore be very awkward to pick one of the other sounds as the basic allophone and write a rule to turn it into [R]. It is easier to take [R] as the basic allophone and write rules to turn it into each of the other sounds.
Hence, in the phonemic representation, only /R/ occurs. Farsi has two phonological rules which convert the phonemic representation into a phonetic one:
/R/ becomes voiceless ([R*]) at the ends of words;
/R/ becomes a flap ([D]) between vowels.
If neither rule applies, then /R/ is pronounced [R], the voiced trill. no title