It is well known that mental state verbs are difficult to acquire, but little is known about the acquisition of mental state language encoded through intonation. Puerto Rican Spanish (PRS) has at least three intonation contours available for marking polar questions (PQs): ¡H*L% marks an utterance as a PQ; H+L*L%, in addition to doing the former, conveys that the speaker has a belief about the (p)roposition and L*HL% marks the utterance as a PQ in addition to marking the speaker's disbelief regarding p. A longitudinal study of two PRS-acquiring children (1;07-3;06) and their caretakers was carried out, analyzing 661 PQs from child speech and 4,574 from child-directed speech. Results show that while all three contours are used in child-directed speech, children almost categorically produce the contour that does not convey any specific mental state. Almost no tokens of the contour conveying that the speaker has a belief about a proposition were found in child speech (4/661 total PQs), and these only appeared after 2;08. No felicitous, nonimitative uses of the contour that conveys a speaker's disbelief were found in child speech. Like other mental state language, intonation conveying epistemic information appears to emerge relatively late in child production.