A set of pragmatic rules of Subject Pronoun (SP) use in native speaker discourse has been defined in terms of pragmatic and discourse notions. The rules we propose attempt to provide a more explanatory account for SP use in Spanish discourse. The "Salient Referent" and "Switch Focus of Attention" rules are rooted in the tendency in language use to implicate an alternative interpretation. "Contrastive Focus" rule uses a stressed overt subject whenever it introduces new/non-presupposed information (typically postverbal), and when it is in (explicit or implicit) opposition to another referent in the discourse. "Pragmatic Weight" rule uses the overt SP yo with speech act verbs of claiming, belief, opinion, emotion, or knowledge to add pragmatic weight to your utterance, to take a firmer stance, to express a greater stake in, or emotional commitment to your assertion or to express that your utterance is highly relevant. "Epistemic Parentheticals" rule uses a null subject in epistemic parentheticals to evaluate the previous or subsequent utterance, or to hedge or mitigate the strength of, or express an evaluative commentary on the utterance. It is of the ultimate importance to have the above mentioned pragmatic rules of SP use included into the speech practice exercises for Spanish L2 strudents.