*Reference: Geffen, S. & Mintz, T. 2014. Can You Believe It? 12-Month-Olds Use Word Order to Distinguish Between Declaratives and Polar Interrogatives. Language Learning and Development. DOI: 10.1080/15475441.2014.951595.
(5) 5.4.3, cross-linguistic variation: “Spanish does not show the same improvement…BHMM-T models do not differ from the baseline BHMM” — It sounds like whether infants heed utterance type as a cue may need to be learned, rather than just being a thing they do. Though since it doesn’t actually harm (it just doesn’t help), maybe it’s okay for infants to try to use it anyway in Spanish. However, just brainstorming about how infants might learn to pay attention to word type…perhaps they could notice word order differences across utterance types (i.e., use various cues to identify utterance types and then see if word order as defined by specific recognizable words — rather than grammatical categories — seems to change). Then, if word order varies, use utterance type information for categorization; if not, then don’t.