The main goal of this paper is to study the vitality of the subjunctivein theSpanish speech of Mexico City and find alternations with theindicative. To this purpose 1164 samples of subjunctive forms in18 speakers from the Sociolinguistic Corpus of Mexico City wereexamined. As linguistic variables, tense, the conventionality of theconstruction, the form of the utterance, its syntactic context, andmain semantic-pragmatic values were analyzed; polarity, factuality,probability, assertiveness and interchangeability with the indicativewere also taken into account. The sociolinguistic variables consideredwere level of education, age, and gender. The study reaffirms the fullvitality of the subjunctive (especially in people with more education,youth and women). The most common subjunctive tenses are thepresent and the past. Syntactic contexts and semantic and pragmaticvalues are important to characterize the use of the subjunctive, but inorder to understand the alternation with the indicative, it is necessaryto consider the factuality, probability and assertiveness involved ineach specific instance. More detailed study of the 439 cases of relativeinterchangeability with the indicative could be carried out.The main goal of this paper is to study the vitality of the subjunctivein theSpanish speech of Mexico City and find alternations with theindicative. To this purpose 1164 samples of subjunctive forms in18 speakers from the Sociolinguistic Corpus of Mexico City wereexamined. As linguistic variables, tense, the conventionality of theconstruction, the form of the utterance, its syntactic context, andmain semantic-pragmatic values were analyzed; polarity, factuality,probability, assertiveness and interchangeability with the indicativewere also taken into account. The sociolinguistic variables consideredwere level of education, age, and gender. The study reaffirms the fullvitality of the subjunctive (especially in people with more education,youth and women). The most common subjunctive tenses are thepresent and the past. Syntactic contexts and semantic and pragmaticvalues are important to characterize the use of the subjunctive, but inorder to understand the alternation with the indicative, it is necessaryto consider the factuality, probability and assertiveness involved ineach specific instance. More detailed study of the 439 cases of relativeinterchangeability with the indicative could be carried out.El principal objetivo de este artículo es estudiar la vitalidad delsubjuntivo en la lengua hablada de la ciudad de México y detectarlas alternancias motivadoras de variación con el indicativo. Paraello, se consideran 1164 muestras de subjuntivos procedentesde 18 informantes del Corpus sociolingüístico de la ciudad deMéxico. Como variables lingüísticas, se analiza el tiempo verbal,la literalidad de la construcción, la modalidad del enunciado, elcontexto sintáctico, los valores semántico-pragmáticos, así comola polaridad, la factualidad, la probabilidad, la asertividad y laintercambiabilidad con el indicativo. Las variables sociolingüísticasson la procedencia del dato, el nivel de estudios, la edad y el género.El estudio reafirma la plena vitalidad del subjuntivo (especialmenteen las personas con más estudios, los jóvenes y las mujeres). Los tiempos verbales subjuntivos más comunes son el presente y elpretérito. Los contextos sintácticos y los valores semánticos yenunciativos son importantes para caracterizar el uso del subjuntivo,pero para expresar la alternancia con el indicativo debe considerarsela factualidad, la probabilidad y la asertividad implicadas en cadaejemplo específico. Deberá profundizarse en especial en los 439 casoscon cierta intercambiabilidad con el indicativo.