Mm? Not sure about the restrictive nature of that statement. On formulaic explanations:Andrew Patterson wrote:
Grammar is of use to native speakers in exactly the way that Larry said and that especially includes remoteness for modal verbs and the subjunctive, and retrospection for perfect tenses; indeed as native speakers we can go into the deep philosophical stuff that we shouldn't dream of discussing with our students except perhaps at proficiency level.
Such analyses have resulted in second language learners being instructed to simply learn formulaic phrases to express polite requests, indirect commands, conditionality, etc. with little or no explanation for why the tense marking in the phrases they are asked to memorize does not correspond to temporal uses of tense.
http://www.sussex.ac.uk/Users/vyv/Exper ... eaning.pdf