Although conditional clauses are often called if-clauses, they don’t always include the word if! In more formal situations, we use a technique called inversion where we reverse the order of the subject and the verb. These clauses are known as inverted conditionals or sometimes reduced conditionals.
Inverted conditionals contain inversion instead of if. Inversion means that we reverse the order of the verb and the subject. This technique is typically seen in more formal contexts.
To invert sentences in the first conditional, we place the auxiliary should before the subject, followed by the infinitive of the main verb: should + subject + infinitive.
In second conditionals, inversion is used to rewrite if-clauses that contain the verb be. Use the structure were + subject.
To invert third conditional if-clauses, use the structure had + subject + past participle.