Despite the general tendency to find the indicative in subordinate structures requiring the (grammatical) subjunctive in the Spanish of second/third/successive generations of heritage speakers, there are some structures where this tendency is in a less advanced stage. This is case of purpose clauses, as seen in Silva-Corvalán (200[1995]). The current study investigates if, besides acquisitional factors, there are other elements (e.g. position of the subordinate clause) that explain the higher retention of the subjunctive in purpose clauses in heritage Spanish. Since heritage speakers share features with monolingual speakers and L2 learners (Montrul 2005), this study also investigated whether the results by heritage speakers could be compared to what monolingual Spanish speakers do, or whether there are more similarities with the results attested for the L2 learners. Different tests were administered to three groups of college students: New Mexico heritage speakers (different generations), monolingual speakers of Mexican Spanish, and US-born, L2 learners of Spanish. Position of the subordinate clause played a different role between these groups, and it did not significantly contribute to explain the higher retention of the subjunctive in purpose clauses in heritage Spanish. Similarities were found between all groups, but it depended on the type of instrument used.