Congruence and convergence are frequently mentioned to explain crosslinguistic phenomena, such as code alternations, borrowings etc., which arise when languages are in contact (Matras 2009). As a rule, these linguistic processes are generated by the coexistence of languages in the same area over a long period of time (hence the creation of sprachbünde), and by situations of language acquisition and bilingualism. These processes are fueled by the acquisition strategies developed by plurilingual speakers (Haspelmath 1998). Congruence and convergence are often used as synonyms to name the linguistic factors that shape the material (linguistic matter) and the modes of organization (patterns) of languages in contact (Matras 2009: 148), but sometimes these terms may refer to distinct linguistic processes. In this contribution, convergence and congruence are discussed in the light of the socio-historical and linguistic development of Creole languages. The meaning and use of these notions are examined through a discussion of the case of nominal agglutination (i.e. the reanalysis of the French Determiner + Noun sequences into new lexical units), presented by Baker (1984) as an example of transfer of a Bantu substratum in the development of Isle de France Creole (i.e. French Creoles from Mauritius, Rodrigues and Seychelles). Since Weinreich (1953) and Haugen (1956), language contacts are known to foster the emergence of diaphonemes and diamorphemes, that is linguistic units which span languages in contact and are perceived by bilingual speakers as identical. These interlingual phenomena bear both on linguistic materials and on modes of organization. The notion of conceptual change of Jarvis and Pavlenko (2008) describes the conditions that trigger these crosslinguistic effects. To pose that the appropriation of the dominant language of a colony by plurilingual subalterns is at the origin of creolization is to accept that the emergence of Creole languages follows a course where transfer, convergence and congruence between languages in contact, and other general learning processes are at play. The crystallization of these learner varieties is made possible because of the development of socialization among the slaves, and of the related sociolinguistic phenomenon of focussing (Lepage & Tabouret-Keller 1985). Gumperz and Wilson (1971) and Myers-Scotton (2002) define the socio-linguistic and cognitive dimensions of convergence while Baptista (2020) uses the notion of congruence to describe the same linguistic phenomena. For these researchers, convergence and congruence, are unitary processes that engender new combinations of units and functions in languages in contact. For other researchers (for instance, Olko, Borges and Sullivan 2018), convergence or congruence is the result of a sum of mechanisms of linguistic change, including grammaticalization, lexical and grammatical borrowing and reanalysis. In the present paper, convergence and congruence are defined as processes based on targeted linguistic transfer which, according to the dynamics of the languages in contact, give rise to reanalysis of the model languages, leading to the creation of new grammatical meanings in the replica languages. If the link is direct between congruence, convergence and reanalysis, i.e. the reinterpretation of the units and categories of the model language, it is indirect vis a vis grammaticalization (Hopper & Closs-Traugott 1993: 220). Convergence and congruence, like other processes, contribute to the development of grammaticalization in emerging languages. Nominal agglutination in French-related Creoles is of two types: a) a consonant is added to a French etymon beginning with an initial vowel; b) a syllable derived from the French determiner (mau. di, li etc.) agglutinates with the French lexical etymon to form new Creole lexemes, examples lera (rat) (from) < (fr. le rat), dizef (eggs) < (fr. de l’œuf), lizje (eyes) < (fr. les yeux) etc. According to Baker (1984), the massive presence of agglutinated nominal forms of the second type in the Creoles of Mauritius, Rodrigues and the Seychelles is due to the presence of Bantuphone slaves in Mauritius during the period of formation of the so-called Isle de France Creole (IdFC), i.e. between 1773 and 1810. Baker (1984: 111) sketches an acquisition scenario whereby the Bantuphone slaves, the majority of the inhabitants of Ile de France at that time, reanalyze the Determiner + Noun sequences of French into unique lexical items because of the transfer of their knowledge of Bantu class markers, leading to a case of isomorphic convergence (Baptista 2020). The paper attempts to show that factors other than convergence and congruence could be at play in the inception of nominal agglutination and more widely of creolization in French Creoles. In the light of the definitions of convergence and congruence proposed, the paper investigates the phenomenon of lexical reanalysis called nominal agglutination, keeping in mind that transfer presupposes the identification of similar sites in the target language and that any isomorphic convergence or any congruence implies that identities have been perceived between the languages in contact. The paper claims that nominal agglutination in French Creoles cannot be considered to constitute a strict case of convergence or congruence in spite of Baker (1984), Myers-Scotton (2002) and Baptista (2020)’s analyses. A cursory examination of the system of class markers in Bantu languages shows that the nominal morphology of these languages is different from that of French. The nominal classes of the Bantu languages and the French NP and its agreement specifiers are organized differently on the morphological and semantic levels. Of course, speakers of Bantu languages tend to be sensitive to prefixes in the model NP and tend to add augments to the substantival base of the model language in certain contexts. However, these arguments are not sufficient to prove that nominal agglutination in French-related Creoles a case of congruence or convergence. Nominal agglutination in French Creoles has been and is produced by multiple factors, from the conservation and the intra-systemic generalization of regional uses of French to possible partial transfers between the languages of the slave populations and colonial French during creolization. Understanding creolization as a case of acquisition of the dominant language of the colony by multilingual adults presupposes an understanding of the conditions that govern the mobilization of convergence or congruence and other linguistic and cognitive mechanisms of transfer, analogy, reanalysis, convergence and congruence. Sociohistorical factors are also to be taken into account in creolization because they shape the very nature of inter-linguistic contacts.