In this paper, we explore three issues related to the acquisition of mood selection in Spanish relative clauses by second language (L2) and heritage (HL) speakers of Spanish: (1) whether HL speakers are more native-like than L2 learners; (2) whether the speakers' performance differs depending on task modality (written vs. oral), since HL speakers are known to perform better in oral tasks and L2 learners tend to do better in written tasks; and (3) whether knowledge of French as an L1/dominant language (DL) has an impact on the acquisition of Spanish subjunctive, since both languages include this mood in their grammars, but it is used more productively in Spanish. Results from a sentence combination felicity task (SCFT) in Spanish-in written and oral forms-and a written elicited production task (EPT) in French, administered to advanced L2 and HL speakers of Spanish whose L1/DL is French and two monolingual (Spanish and French) control groups, revealed that L2 learners pattern more closely with the control group than HL speakers in the SCFT, both written and orally. In the EPT, all bilingual speakers display higher levels of subjunctive use than the control group, showing a potential influence from the L2/weaker language on the L1/DL. Languages 2018, 3, 31 2 of 23 these two groups of speakers may be task-induced. Specifically, L2 learners, who have received more instruction in the classroom, tend to obtain better results in tests that maximize explicit or metalinguistic knowledge (e.g., written tasks), whereas HL speakers, who typically acquire their heritage language at home, are more accurate in tests that measure implicit knowledge (e.g., oral tasks) (Bowles 2011;Montrul 2012;Montrul et al. 2008). This finding will be discussed in more detail in Section 2.2.In turn, tapping into language typology, it has been discussed whether the presence of the subjunctive mood in the L1 represents an advantage in the L2 acquisition of mood selection in Spanish relative clauses. Specifically, when comparing L1 French (L1FR) with L1 English (L1EN) speakers learning Spanish as an L2, it has been found that L1FR speakers acquire the indicative-subjunctive contrast faster and pattern more closely with Spanish native speakers than L1EN speakers (Borgonovo et al. 2008;Boudreau 2007). However, as Boudreau (2007) claims, differences could be, again, task-induced, since the participants in her study performed different tasks. Namely, the L1FR group completed a written sentence combination felicity task (Boudreau 2007), while L1EN participants completed an appropriateness judgment task (Borgonovo et al. 2008). When comparing L1EN learners of Spanish with French as a third language (L3) with L1EN learners with no knowledge of French, Restorick Elordi (2012) found indications of positive cross-linguistic influence from the L3 to the L2, suggesting that L2 learners are at an advantage acquiring an interface phenomenon if they are also learning an L3 that presents the same phenomenon. However, it is important to take into account that, even ...