The ability to learn a foreign language, language aptitude, is known to differ between individuals. To better understand second-language learning, language aptitude tests, tapping into the different components of second-language learning aptitude, are widely used. For valid conclusions on comparisons of learners with different language backgrounds, it is crucial that such tests be language neutral. Several studies have investigated the language neutrality of the freely available LLAMA tests (Granena, 2013;Rogers et al., 2016Rogers et al., , 2017. So far, comparing a number of L1 backgrounds, including those using different writing systems such as Arabic and Mandarin, no significant differences between participants have been found. However, until now, neither participants with agglutinative language backgrounds nor with first-language backgrounds that use multiple writing systems have been included. Therefore, this study selected participants from three different first-language backgrounds: Dutch (non-agglutinative, phonogram/Latin alphabet), Hungarian (agglutinative, phonogram/Latin alphabet), and Japanese (agglutinative, phonogram/syllabic alphabet and logogram/Japanese kanji). The participants performed three subsets of the LLAMA test. Significant differences between the groups were found on two of these tests: The ability to implicitly recognize sounds (LLAMA_D subtest) and inductive grammar learning ability (LLAMA_F), but no differences were found on vocabulary learning ability (LLAMA_B). Additionally, for LLAMA_B, the number of languages learnt was a significant covariate, confirming earlier findings that some subtests seem to be linked to language learning experience. We discuss the implications of our findings on the validity of the LLAMA_D and LLAMA_F subtests. MOMO MIKAWA