The paper presents, in the light of the psychosystematics of a language, a contrastive analysis of the definiteness of the noun in the French and Croatian languages which is carried out on the morphological and semantic level with respect to the articles and their equivalents, including certain references to the English and Italian languages. The issue of acquisition, use and teaching of articles is studied with the emphasis on the cognitive aspect in the form of metalinguistic, interlingual and multilingual awareness development. The theoretical part of the paper is followed by psycholinguistic research on mastering of the French article system and the awareness of the existence of a universal category of indefiniteness/definiteness, before and after inductive and constructivist approach to the problem among Croatian secondary school pupils learning French as second or third foreign language and among students of the French language. From the initial belief that articles denote the gender, number, and case of the noun which it precedes to the expression of its indefiniteness/definiteness, it can be concluded that the fundamental category of an article is extensiveness (cf. Guillaume 1919). Compared to a language, such as Croatian, which is not familiar with this small word officially, attention is drawn to other various realisations of the noun determination which are expressed on a syntactic or lexical plan in the Croatian language (cf. Kordić 1993, Silić 2000, Pranjković 2000, Šarić 2002, Marković 2002, Znika 2005). Therefore, apart from the article, the subject of this research is noun as well, since the (in)definiteness is considered to be its inherent category (cf. Marković 2002) and the findings which are presented are relevant to its analysis. By analysing the corpus, which includes several contemporary novels originally written in French and their translations into Croatian, and the terms spoken in the standard and colloquial Croatian language, it is concluded that the Croatian language can truly confirm the existence of an equivalent to an indefinite article or at least an emerging article (cf. Bajrić 2006). However, it still primarily appears for stylistic reasons and cannot have the same status as the French article (cf. Kuzmanić (Pivčević), Frleta 2013) because it does not follow special usage rules in the Croatian language and is not a mandatory element of the nominal syntagm. The complexity of the subject matter can be seen in numerous problems that occur in the course of the acquisition of the French article system by native speakers of Croatian, as well as during its implementation in the classroom. It is concluded that, considering Croatian language does not have a category of definite/indefinite article, Croatian pupils/students of French mostly make errors by omitting an article or by choosing an inappropriate article type in French (fluctuation hypothesis) (cf. Avery, Radišić 2007, Ćulinović 2010, Balenović 2012). The contrastive analysis in the classroom is more than welcome not only between the mother tongue, in which speakers have a high level of language sense and linguistic intuition (cf. Bajrić 2009) and the foreign language being taught, but between all the other languages used by the teacher and its audience to some extent (development of the metalinguistic and multilingual competence, cf. De Angelis, Jessner, Kresić 2015), which might (statistically significantly) enable the appropriate use of article in French. This conclusion is drawn from the analysis of the results obtained after the implementation of the treatment, i.e. after performing linguistic activities inspired by the constructivist learning theory (cf. Piaget 1923, Vygotsky 1926, Brooks & Brooks 1993, Taber 2011), whereby, the accent was put on the awareness of the universal indefiniteness/definiteness category and from the analysis of the French textbooks and role of grammar in language teaching. Results also indicate that foreign language acquisition does not depend on the intensity of the language use (in the institutional context), but on the methods of language teaching. Moreover, the results have shown need for a constant development of the interlingual awareness and strengthening of confirmation in mother tongue for the purpose of development of the linguistic intuition with respect to the article system and category of indefiniteness/definiteness, as well as the language in general, since pupils/students who use more languages achieve better results. In such a metacognitive environment, students become active and responsible participants in construction of their own knowledge (by thinking, analysing, understanding and applying). Psychosystematics (Guillaume) turns out to be similar to the constructivist ideas regarding construal of thoughts. The results of the comparison of two or more languages may have practical implementations in translating and in a number of other linguistic areas, but the targeted contribution of this theoretical and applied research is specifically expected in glotodydactics. Since other research related to the acquisition of category of indefiniteness and definiteness in various languages did not involve the conduction of any linguistic activities (i.e. the teaching method) and thus did not receive any feedback of this type, this research is considered unique. Its results are especially valuable because, apart from addressing the existing phenomena in the Croatian language regarding the determination of the noun, the proposed didactic activities suggest a more systematic and pragmatic analysis of the grammatical category of articles in French language teaching, as well as other foreign languages in this territory, namely by well-educated, aware and motivated teacher.