I do believe it is an overcorrection. Although in certain regions of the DR there is a problem with the subjunctive mood, judging by what I have observed, the problem is mainly with those verbs of the second and third conjugation (er, ir) in the present tense, first person plural.
In forming the subjunctive, er & ir verbs take the opposite vowel (a) which is the same vowel upon which the stress or accent falls. This causes the first person plural (nosotros ) to sound quite odd, awkward, to say the least.
Ar verbs are not that problematic. They take the opposite vowel (e) and the resulting sound is a very pleasant one: cantemos, bailemos, juguemos, hablemos, preguntemos- in spite of the fact that this vowel also carries the stress.
Let's look at some er/ir verbs – (first person plural - present subjunctive)
comer - comamos.ser - seamossaber - sepamos
caber - quepamosvenir - vengamos decir - digamos
salir - salgamos morir - muramos
The brain seems to have a disdain for such sounds; it likes comfort. Educated people accept the phonetic discomfort of these verbs because we know that they are grammatically correct. Many of us were exposed to them from early childhood through a decent learning environment, reading, TV and radio programs, good teachers, etc. and we know that they are supposed to be just so in spite of their ungraceful sound. What do some uneducated people do with them? I have observed two things:
1. They apply the same rule that governs ar verbs, thus producing an erroneous subjunctive with certain verbs: venguemos, salguemos.
2. They accept the opposite vowel (a) but transfer the stress to the third syllable. The word then becomes, by its accentuation, esdr?jula: mu?ramos (also incorrect ).
Today, radios and TV sets abound and campesinos hear the news and watch telenovelas. There is language input like never before. In their effort to absorv and produce what they hear, oftentimes they err. Perhaps their children or maybe their grandchildren will get it right.
Norma