animacy in Rioplatense Spanish

Rioplatense Spanish grammaticalises animacy through differential object marking: a direct object naming a human being, or an animal treated as an individual, is preceded by the marker a, and an inanimate object takes no marker at all. The contrast between busco a mi amigo and busco un plomero shows that the marker depends on specificity as well, so animacy is one of two conditions rather than the whole trigger, and llamé un taxi shows the inanimate case failing on animacy alone. Nothing in the language inflects a noun for a point on the animacy scale and no agreement pattern varies with it, so the ranking is visible only in what it triggers, which is the shape the dimension describes. Animacy also constrains the choice between the object pronouns lo and le for many speakers, and it separates the paired question and indefinite words quién from qué and alguien from algo, which distinguish a person from a thing as a matter of the word chosen. The marking is recorded as conditioned because it appears only on an object meeting both conditions and nowhere else in the clause.