CONDITIONAL SENTENCE Conditional sentences There are five main ways of constructing conditional sentences in English. In all cases, these sentences are made up of an if clause and a main clause. In many negative conditional sentences, there is an equivalent sentence construction using "unless" instead of "if". There are five main ways of constructing conditional sentences in English. CONDITIONAL SENTENCE TYPE USAGE IF CLAUSE VERB TENSE MAIN CLAUSE VERB TENSE Zero General truths Simple Present Simple Present Type 1 A possible condition and its probable result Simple Present Simple Future Type 2 A hypothetical condition and its probable result Simple Past Past Future Type 3 An unreal past condition and ots probable result in the past Past Perfect Past ...