There was an interesting exchange on Twitter recently on the topic of the subjunctive.
That seems an unlikely opening sentence to any blog post, so I should be specific: it was about the case that to learn a language, at least initially, you do not need to learn all the detailed aspects of its grammar and general form. The example given was that it is possible (allegedly) to get a long way in Spanish without needing the subjunctive.
This argument had its proponent and its opponent. I do not fall into either category completely, but I veer more towards the opponent in this case.
The subjunctive is a verbal “mood”, rarely used in English (usually to mark obligation or recommendation: “It is essential that you be there“) but very common in Spanish. Furthermore, in Spanish its form is more likely to vary (in English, the subjunctive form is as often as not the same as the “normal” indicative: “It is essential that you come“).
Spanish has maintained the subjunctive in wide use, even in the colloquial spoken language. It is obligatory in many instances (vienes “you come”; es muy importante que vengas “it is very important that you come”); and it is vital to meaning in others (aunque vienes “even though you are coming”; aunque vengas “even if you come”).
The essential argument that it is not necessary to know every aspect of a language’s structure at the outset is undoubtedly true. After all, when we teach any language, we tend to start with the “normal” indicative present tense and then introduce other tenses and forms as we go along.
When I teach Spanish to community groups, I often avoid teaching verb forms at all initially. Instead of learning puedo “I can”, puedes “you can”, podemos “we can” and so on, it is possible for example to learn “es posible por mí… por ti… por nosotros” and then also “es necesario…”, “es bueno…” and so on for basic phrases (thus we can already express possibility, necessity and desirability without any verb forms).
Therefore, I do see the argument that the subjunctive is not necessary at, or even particularly near, the outset.
However, it is a simple reality of the structure of the Spanish language that the subjunctive is widely used (and, as noted above, often decisive as to meaning).
Therefore, it is not quite accurate, in my view, to say it can be delayed indefinitely or even for any real length of time.
Spanish also, for example, has three past tense forms [strictly two, plus a present form which indicates past]. I would contend that in fact it is more important to know the present subjunctive than to know the preterite (one of those past tense forms), as it is more likely to arise sooner and in a way which may be decisive as to meaning. Most native speakers will understand a foreigner mixing past tense forms, but may be thrown by the use or non-use of the subjunctive.
Therefore, reluctantly, I conclude the subjunctive (at least in the present form) is necessary fairly early. It simply cannot be avoided for too long without sounding ludicrously stilted or just plain wrong.
I would suggest the same applies to Italian and Portuguese (perhaps not so much to spoken French).