 As mentioned by Singerman (2018), the case markings are used in complementary distribution, unless they are referring to time, in which case LOC (on Portuguese loan-words), INS (on Tuparí temporal expressions) and OBL (in finite embedded clauses marking time) may be used.As discussed by Singerman (2018, section 2.4), the nuclear case is subject to strict grammatical constraints.It is required on all NP subjects, as well as on strong pronouns that introduce a new topic.