Absolute and construct form (or state) of nouns is a morphosyntactic phenomenon found in Semitic, Berber (Mettouchi 2014), and in a number of African languages like Tswana and Wolof: it generally consists of head nouns bearing a marker in the case of nominal modification, in which case the noun is said to take the construct form. Outside of modification, the absolute (e.g citation form) form is used. In a typological survey, Creissels (2017), makes different cross- linguistic observation based on a larger sample which also adds other languages like Anejom from Oceania and Hungarian from Eurasia: There are no cross-referencing features of the modifier on the noun; the construct form can co-occur with other marked features of the noun (e.g. number); cross-linguistic variation exists in the type of modifiers that trigger the construct form and in the morphological nature of the construct marking. This paper will present novel data from Kibiri, an underresearched severely endangered language spoken by 32 people at Kikori district in southern Papua New Guinea; it forms, with the dialect Porome [prm], the Kibiri-Porome isolate. So far, the construct form of nouns have not been identified in Papuan languages. Ongoing analysis shows that Kibiri does exhibit an absolute and construct form of nouns (like it has been identified for Porome, Petterson 2019) and that it confirms the previous typological observations. However, what sets Kibiri apart is the fact that the absolute and construct forms are sensitive to word order and that they are optional in the case of modification with adjectives, numerals and quantifiers, but construct form is obligatory and word order is rigid in possessive, relative and compounding constructions; also there are very rare cases where a construct-marked noun has been lexicalized as a verb. The talk will be based on already existing descriptions of construct form from other languages (Anejom, Nêlêmwa, Eton, Hebrew, etc), with a comparison with new data from original fieldwork on Kibiri, taking a variation approach (optionality and word order).