When do you follow tal vez with an indicative mood and when do you use a subjuctive mood?
Most textbooks say tal vez is followed by subjuctive verb but my instructor says it can also be followed with a indicative verb. Are there rules as to when each one should be used? Gracias
Following it with the subjunctive indicates a greater degree of doubt, but I don't think there is a precise rule or even a way to measure the precise degree of doubt.
There is a discussion here with a number of good comments, in particular:
It would be great to have one rule covering all uses of the subjunctive, but the Grammar Gods are not so kind. In this case, yes, tal vez (and I prefer two words) expresses uncertainty, but that in itself doesnt trigger the subjunctive. Tal vez isnt a conjugated verb that governs the mood of the sentence.
When you use tal vez, a nuance comes into play as you consider uncertainty: If the uncertainty you have in mind is probable, then you may use the indicative: Tal vez quiere beber algo caliente. If the uncertainty, however, refers to something that is improbable or doubtful, go with the subjunctive: Tal vez quiera beber algo caliente.
Now, probable and improbable are highly subjective, but, ultimately, you (the speaker) decide what is probable (indicative) or improbable (subjunctive). It is your sentence, after all.
Both are correct.
1 Tal vez él quiere beber algo caliente. (indicative implies a greater probability or more certainty-"pretty sure" or "probably so")
2 Tal vez él quiera beber algo caliente. (subjunctive implies greater doubt or uncertainty-"maybe, but probably not")