A conditional sentence consists of two clauses which are called antecedent and consequent clauses. An antecedent clause expresses the condition and it might be syntactically dependent on the consequent clause.
Semantically, conditional clauses can be mainly categorized into (i) factual conditionals, (ii) counterfactual conditionals, (iii) concessive conditionals, and (iv) non-predictive/peripheral conditionals. These, as well as other less canonical conditional constructions, are described in detail in the following sections.