The English subjunctive mood is used to express situations that are hypothetical , unreal or to express a proposal or intention about the future. However,it is only used when we want to sound very formal. This table contains the most common verbs, expressions and adjectives that can be followed by the subjunctive form.
In this book, Michela Ippolito proposes a compositional semantics for subjunctive (or would) conditionals in English that accounts for their felicity conditions and the constraints on the satisfaction of their presuppositions by capitalizing on the occurrence of past tense morphology in both antecedent and consequent clauses. Very little of the extensive literature on subjunctive conditionals tries to account for the meaning of these sentences compositionally or to relate this meaning to their linguistic form; this book fills that gap, connecting the different lines of research on conditionals.
There exists quite a variety of statements which are in some sense 'subjunctive'. The best known of these are the so-called 'counterfactual conditionals' which state that if something which is not the case had been the case, then something else would have been true.