From the introduction: "There are several allomorphs of the morpheme indicating second person imperative and several of the morpheme indicating first person imperative in Seri. Since these allomorphs are for the most part suppletive in each case, it is necessary to posit two multi-clause spelling rules to account for them. In this paper I will present evidence for the analysis I have adopted which to the best of my knowledge accounts for all of the second person and first person imperatives in Seri."
Marlett, Stephen A.
"The imperative morpheme in Seri,"
Work Papers of the Summer Institute of Linguistics, University of North Dakota Session: Vol. 21, Article 8.
Available at: https://commons.und.edu/sil-work-papers/vol21/iss1/8