3.32 Geminate-Contraction P-31.

Ordinarily, when two identical consonants form a cluster, the cluster simplifies to a single consonant. In some cases, like /gg/ /rr/ and /jj/ we already have rules which account for the contraction, or could easily be modified to do so. However, even those consonants for which no existing rule accounts for deletions undergo Geminate-Contraction.

An ex. is //dd///d/ as in /ama-yi:mi-duj/ 'on the apple tree', with /yi:mid/ as the stem and suffix //-ruj///-duj/ Similarly, note //nn///n/ as in the usual pronunciation of /nganu-mu(n)=na-ny/ 'I saw his foot', with /mu:n/ 'foot'. In new compounds of this type, the geminate cluster is occasionally heard on the surface in slow speech, but in more casual styles the contraction is virtually automatic.

(P-31) Geminate-Contraction
C1 → Ø // ___ -C1

Of course, it is arbitrary to say that the first rather than the second member of the cluster is deleted. We prefer to transcribe the surface forms as though the first member were deleted, for two reasons. First, in the majority of non-geminate cluster simplifications, it seems that the first consonant is the more likely to be deleted. Second, our transcription makes it easier for readers to identify the morphemes correctly, on the assumption that omission of a morpheme-final segment is less likely to cause misidentification than omission of a morpheme-initial segment.