Conditional sentences are sentences expressing factual implications, or hypothetical situations and their consequences. They are so called because the validity of the maun clause of the sentence is conditional on the existence of certain circumstances, which may be expressed in a dependent clause or may be understood from the contenxt.
A full conditional sentences (one which expresses the condition as well as its consequences) therefore contains two clauses: the dependent clause expressing the condition, calles the protasis: and the main clause expressing the consequence, called the apodosis. An example of such a sentence is the following: If it rains, the picnic will be cancelled.
Here the condition is expressed by the clause "If it rains", this being the protasis, while the consequence is expressed by "the picnic will be cancelled", thus being the apodosis. (The protasis may either precede or follow the apodosis: it is equally possible to say "The picnic will be cancelled if it rains"). In term of logic, the protasis corresponds to the antecedent, and the apodosis to the consequent.
Laguages use a variety of grammatical forms and constructions in conditional sentences. The form of verbs used in the protasis and apodasis are often subject to particular rules as regards their tense and mood. Many languages have a specialized type of verb form calles the conditinal mood.
Sumber: http://en.wikipedia.org/wiki/Conditional_sentence
Sumber: http://en.wikipedia.org/wiki/Conditional_sentence
