# Determining underlying representation

I'm really confused about how to determine underlying representation. Every thing I read seems to contradict the last.

Trying desperately to solve this problem and I just seem to be going in circles with both 1 and 2. Any suggestions?

**In Maga Rukai, an Austronesian language spoken in Taiwan, certain prefixes show an alternation between a mid vowel and a high vowel.

``````  1) For each alternation, state the underlying representation. Justify.
2) What determines whether the prefix vowel is mid or high? State the rule that would describe this.**
``````

o ~ u dynamic verb marker

o-kamɨ ‘back’ u-cŋulu ‘connect’

o-lapɨ ‘hunt without dogs’ u-lupu ‘hunt with dogs’

i ~ e negative marker

i-tukruː ‘not hit with stones’ e-kapliː ‘not hold with hands’

i-ulpuː ‘not hunt’ (with dogs) e-lalpɨː ‘not hunt’ (without dogs)

si ~ se to wear

si-slivi ‘wear beads’ se-kceŋe ‘wear pants’

si-krɨkrɨ ‘wear a necklace’ se-kcabu ‘wear leggings’

te ~ ti to make

te-kceŋe ‘make pants’ ti-slivi ‘make beads’

te-tovnaː ‘build a hut’ ti-kunu ‘make a skirt’

te-sdamraː ‘cook a side dish’ ti-krɨkrɨ ‘make a necklace’

ke ~ ki harvest

ke-teθo ‘harvest turnip’ ki-sito ‘harvest peanut’

ke-bləblə ‘harvest bamboo shoot’ ki-lpɨlpɨ ‘harvest peas’

ke ~ ki passive

ke-ɖoɖoː ‘be awaited’ ki-klukluɖu ‘be frightened’

ke-kθabɨ ‘peeled’ ki-tɨtɨ ‘be bitten’

You need to formulate two theories about the two things that alternate and compare those theories to decide which is best. One theory will be that the mid vowel is underlying and a high vowel is sometimes derived from it. The other theory will be that the high vowel is underlying and a mid vowel is sometimes derived from it. Formulate the rules required for the two theories, if possible, and compare the rules for naturalness (assimilations are good). If one of the theories cannot be made to work at all, because there is no way to predict the observed forms, your work is done -- the other theory must be correct.

If this doesn't work, you might have to resort to a more complicated theory in which the underlying form is different from both the surface vowels observed.

These are just general suggestions -- I didn't try to work your problem.

Good luck.

2) The rule for the Maga Rukai prefixes alternation is obvious: if the first syllable after the prefix has a high vowel (i, ɨ, u), you choose the high variety of the prefix (u-, i-, si-, ti-, ki-), but if the first syllable after the prefix has a nonhigh vowel (e, ə, o, a), you choose the mid variety of the prefix (o-, e-, se-, te-, ke-).

1) As for this question, it is your job to decide and justify. Use the answer by @Greg Lee, and also use this related question: How to determine which phoneme a group of allophones realizes?. Ths paper is also good, it has step-by-step solutions of problems similar to yours: Morphophonemics: determining underlying forms and rule interactions.

• I think you mean high vowel, not high syllable. Commented Feb 6, 2015 at 22:39
• @GastonÜmlaut - Yes, sure, a syllable with a high vowel. Do you think I should correct it? Commented Feb 6, 2015 at 23:54
• Linguists will know what you mean, but I think it would be clearer that way so, yes. Commented Feb 8, 2015 at 2:01
• @GastonÜmlaut - Ok, corrected. Commented Feb 8, 2015 at 2:09

I disagree with Yellow Sky's assertion that the answer is obvious. Given the accompanying instructions, that answer is also incorrect. [Change of heart]. Okay, maybe I misinterpreted the instructions and YS proposed rule is possible. It depends on what your instructor means by "rule". Conventionally, these kinds of problems require a specific formal mechanism to change the underlying form into the surface form, and a statement of correlation would not suffice. That is the point of requiring an explicit underlying form. But your instructor might also allow an observation of correlation without a specific "how" as constituting a rule. You can probably tell if you've gotten instructions in rule-formalism.[/Change of heart]