Differences between sound systems and grammars of languages are readily apparent, making it obvious that bilinguals must somehow navigate these differences in acquiring the two languages. Also the words of the languages (both their meanings and patterns of use) may differ in subtle ways for many domains, such as color (Kay et al., 1997; Roberson and Davidoff, 2000; Regier et al., 2007), motion and movement (Talmy, 1985; Slobin, 1996), and emotion (Wierzbicka, 1999) among others. Differences in the way how languages map words onto referents exist even for common concrete words for familiar objects (e.g., Malt et al., 1999; Pavlenko, 2009; see Malt and Majid, 2013 for review). This implies that bilinguals must either develop and maintain two separate, monolingual-like naming patterns in their two languages or in some way develop a more shared semantic system. Ameel et al. (2005) termed the first possibility the two-pattern hypothesis (see Figure 1B). This hypothesis predicts that the naming patterns of both a bilingual’s languages will be identical to the monolingual naming patterns of these languages. In contrast, the strong one-pattern hypothesis suggests that bilinguals fully merge their naming patterns. In this completely converged naming pattern, the patterns in the two languages are identical to each other (Figure 1C). Ameel et al. (2005) tested these hypotheses by asking functionally monolingual Belgian speakers of French and of Dutch and Belgian bilingual speakers of both languages to name pictures of household containers and dishwares. They found that the bilinguals’ naming patterns in the two languages were more similar than were those of the monolinguals of each language. This finding is consistent with the one-pattern hypothesis. However, the convergence was only partial, pointing to a more moderate version of the one-pattern hypothesis (Figure 1D). The initial model with six correlations between each pair of language groups is represented in Figure 1A.