Mojeño Trinitario shows a split-intransitivity system combined with a differential marking pattern for third-person A/S. The pronominal system of the A/S paradigm is quite complex. There are five markers for third person, specified for humanness, number, gender, and speaker's gender. Interestingly, these markers compete with another marker for third person, the prefix ty-, which is semantically unspecified. The most important factor in the distribution of the two alternatives for third-person A/S marking is transitivity. The transitivity of a construction cannot be determined just by the valence of the root (the number of participants) but depends also on other parameters such as the semantic characteristics of the participants and the discourse function of the utterance. As a consequence, transitivity must be seen as a continuum rather than a dichotomy. Since most roots are ambitransitive, transitivity is a category of the utterance level rather than the lexical level. This fluid transitivity is an essential characteristic of Mojeño Trinitario.