There is always a change in pitch after the first mora in the standard Tokyo dialect. So the only patterns that work in that dialect are [歯が]{HL} H(L) [名が]{LH} L(H) Regarding other dialects (like Kansai-ben), I know next to nothing.


下 and 上 are not distinguished by their pitch accent; they are just pronounced differently. した and うえ respectively. Are you perhaps thinking of 下 verses 舌 which do differ as you mentioned?. The difference is apparent when a particle follows: for 下は the accent is as [したは]{LHH} for 舌は is it [したは]{LHL} Per the comment made by @DariusJahandarie, the pitch ...

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