Although English and Spanish share some grammatical structures, they differ in their use ofthe subjunctive mood. As a result of this difference, the acquisition of the Spanish subjunctive mood remains a significant challenge for English speakers. In English, the use of subjunctive forms is limited and structurally different from its Spanish counterpart, leading to difficulties in mastering Spanish subjunctive constructions, especially in desiderative contexts. The objective of this thesis is to analyze how native English speakers acquire the Spanish subjunctive mood, particularly in desiderative contexts, and to determine if factors such as proficiency level and exposure influence this process. This study employs a combination of picture-based completion tasks and truth-value judgment tasks, administered via the online survey platform Qualtrics XM, to evaluate participants' use of the subjunctive mood. The results will be compared with those of native Spanish speakers to identify specific challenges and patterns in L2 acquisition. By examining these factors, this research aims to contribute to the field of second language acquisition and improve teaching methodologies for complex grammatical structures in Spanish.