or (reflected as and in Tocharian B), and Tocharian A e and o stem largely from monophthongization of former diphthongs (still present in Tocharian B). Diphthongs Diphthongs occur in Tocharian B only. Consonants The following table lists the reconstructed phonemes in Tocharian along with their standard transcription. Because Tocharian is written in an alphabet used originally for Sanskrit and its descendants, the transcription reflects Sanskrit phonology, and may not represent Tocharian phonology accurately. The Tocharian alphabet also has letters representing all of the remaining Sanskrit sounds, but these appear only in Sanskrit loanwords and are not thought to have had distinct pronunciations in Tocharian. There is some uncertainty as to actual pronunciation of some of the letters, particularly those representing palatalized obstruents (see below). is transcribed by two different letters in the Tocharian alphabet depending on position. Based on the corresponding letters in Sanskrit, these are transcribed (word-finally, including before certain clitics) and n (elsewhere), but represents , not . The sound written is thought to correspond to a alveolo-palatal affricate in Sanskrit. The Tocharian pronunciation is suggested by the common occurrence of the cluster śc, but the exact pronunciation cannot be determined with certainty. The sound written seems more likely to have been a palato-alveolar sibilant (as in English "ship"), because it derives from a palatalized . The sound ṅ occurs only before k, or in some clusters where a k has been deleted between consonants. It is clearly phonemic because sequences nk and ñk also exist (from syncope of a former ä between them). Morphology Nouns Tocharian has completely re-worked the nominal declension system of Proto-Indo-European. The only cases inherited from the proto-language are nominative, genitive, accusative, and (in Tocharian B only) vocative; in Tocharian the old accusative is known as the oblique case. In addition to these primary cases, however, each Tocharian language has six cases formed by the addition of an invariant suffix to the oblique case — although the set of six cases is not the same in each language, and the suffixes are largely non-cognate. For example, the Tocharian word (Toch B), (Toch A) "horse" < PIE *eḱwos is declined as follows: The Tocharian A instrumental case rarely occurs with humans. When referring to humans, the oblique singular of most adjectives and of some nouns is marked in both varieties by an ending -(a)ṃ, which also appears in the secondary cases. An example is