Introduction

Conditional constructions pose some of the most difficult problems in comparing the grammars of English and of Japanese, especially when attempting to elucidate grammatical contrasts to non-native speakers. It is understandably so because conditional thoughts are among the most complex of mental activities. Compare, for example, conditionals with temporal (Chapter 16) and causal connections (Chapter 17). Although temporal statements involve the speaker’s subjective assessment of the temporal alignment of subordinate and main-clause situations, they are nonetheless the simplest among these three types of clause linkage. Causals are more complex, for causality is interpreted in the speaker’s mind, and is not overtly present in situations in the real world. Conditionals are even more complex and elusive, dealing not only with actual situations in the real world, but also imagined situations in a hypothetical world and comparing how a given situation might arise.

As evidence of the complexity of conditionals, I have been writing academic articles in English for more than two decades. And yet, as a non-native speaker, I have not grasped all subtleties pertaining to English conditional constructions. And when I ask native speakers of English about my uncertainty regarding problematic conditional sentences, it is frequently unclear whether or not the informant and I are talking about the same situation. I therefore utilize diagrams, rather than verbal characterizations about conditional statements. The diagrams in the following discussion are inspired by Fillmore (1990), wherein ω0 stands for the real world, ω1 for a possible (alternative) world, S for the speaker (located in the slot “Now” in the real world when the tense is relevant), -P′ for “not P′” (i.e. denial of the factuality of P′) used to represent counterfactual conditionals.