When items such as "some" and "or" are uttered, the interlocutor can interpret them as the negation of another related item, namely "all" and "and", respectively. In such cases, it is deemed that the interpretation for "some" can be "some, but not all", while the reading for "or" would be "A or B, but not both". This particular usage of "or" is commonly referred to as "exclusive-or". Sentences containing "some" and "or" are considered subinformative when they describe a situation where "all" or "and" could have been uttered instead. Previous literature exploring children's comprehension of these subinformative uses has revealed that preschool-aged children, in contrast to adults, accept sentences with the equivalent of "some" to describe situations where "all" would be more appropriate (PAPAFRAGOU; TANTALOU, 2004; BALE et al., 2010). Similarly, they accept sentences with the equivalent of "or" to describe situations where "and" would be more fitting (TIEU et al., 2017;SKORDOS et al., 2020). Conversely, studies investigating the production of "some" and "or" by children acquiring English have reported that "some" is used to describe situations where the reading "some, but not all" is suitable, and they produce "exclusiveor" before the age of four (MORRIS, 2008;EITELJÖRGE;POUSCOULOUS;LIEVEN, 2018). This disparity between production and comprehension results suggests an asymmetry in child language, with production preceding comprehension. In this dissertation, it is argued that the framework of Optimality Theory (OT) can account for these asymmetries in child language.Considering these observations and the scarcity of studies examining the predictions of OT for semantic-pragmatic phenomena in the context of Brazilian Portuguese (BrP), this dissertation aims to investigate the linguistic behaviour of children acquiring BrP as their first language in the production of "ou" and "alguns." To this end, two corpora of child speech were analysed. The first corpus comprises approximately 119 hours of spontaneous speech recordings involving four children acquiring Brazilian Portuguese between the ages of 2;0 and 5;6, in addition to the speech of 53 adults with whom the children interacted (SANTANA-SANTOS corpus). The second corpus consists of approximately 51 hours of elicited speech recordings of narratives by seven children acquiring Brazilian Portuguese between the ages of 4;3 and 9;0, alongside the speech of five adults with whom the children interacted (AlegreLong corpus). Our findings corroborate the results of studies conducted in English. We observed that the first production of "ou-exclusivo" occurs at 2;4, while the first production of "alguns, mas não todos" takes place at 3;11. We extended the 13 analysis to encompass the production and comprehension proposed by Mognon et al. (2021) for "alguns" to "ou" and we also presented a novel analysis to describe the production and comprehension of "ou" in contexts where its exclusive reading is necessary. Within OT, the asymmetry between the production and comprehension o...