The pitch accent of ～てしまう is fairly obvious. The pitch accent of the て-form is
well-documented and しまう is just a 平板 verb.

As for the contracted forms ～ちまう and ～ちゃう, I have come across conflicting
information both online as well as in my personal observations.

What is the resulting pitch accent when one appends ～ちまう and ～ちゃう to 平板 (する,
言う, 寝る) and 起伏 (来る, 持つ, 食べる) verbs?
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2023-06-20T18:34:27.180
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2023-06-20T18:34:27.180
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pitch-accent auxiliaries
Pitch accent of ～ちまう and ～ちゃう