I came across the following conditional clause while studying a grammar book published by Oxford:
"If you know London so well, you shouldn't have got so hopelessly lost."
The writer of the book has only briefly mentioned that this is a mixed conditional clause (type 1-3) without giving any further explanation in what situation it can be used. I'm already familiar with two other types of mixed conditional clauses (type 2-3 and type 3-2) and have no problem understanding them but this one is causing me some trouble. I need your help. Thanks.
Best Answer
I urge you stoutly to abjure the Trinity. The nth-conditional framework is a pedagogic device which has almost nothing to do with how conditional constructions are actually used.
The sort of conditional you instance is categorized by Declerck and Reed† as an indirect inferential of a sort in which
Nth-conditionals, as they are typically taught, are actualization conditionals, “If P happens, Q happens”: actualization of P causes or triggers the actualization of Q, or at least provides a relevant occasion for the utterance of Q. These conditionals require a sequence of eventualities.
But inferential conditionals present virtually no constraint on the tenses and modes of the verbs. Inferential conditionals are not concerned with the actualization of eventualities but with the truth of propositions: (“If P is true, Q is true”). A proposition may be cast in any tense or mode, but the inference from one proposition to another is always present-tense, although that is rarely made explicit.
† Conditionals: A Comprehensive Empirical Analysis, 2001, 3.6.2, 44-45. The authors’ terminology rests on the traditional conditional template “If P, Q”; they employ P-clause for the condition (IF) clause and Q-clause for the consequence (THEN) clause. Lower-case abbreviations [p], [q] represent the propositions expressed in the clauses P and Q, with '+' and '-' representing positive and negative assertions.