A conditional sentence is composed of two clauses: the antecedent clause expressing a condition, and the consequent clause. The antecedent clause is syntactically dependent on the consequent clause.
Semantically, conditional clauses may be distinguished into i) factual conditionals, ii) counterfactual conditionals, iii) concessive conditionals, and iv) non-predictive/peripheral conditionals. In the following sections, each type of conditional clause, and also other less standard conditional sentences, will be described in detail.