This document discusses different types of conditional clauses in English, known as "if clauses". It describes 6 main types:
Type 0 and Type I deal with real possibilities in the present or future. Type 0 shows a consistent result, while Type I shows a possible result. Type II, III, and mixed types deal with unreal or contrary-to-fact conditions in the present or past. Type II expresses an unreal present condition, Type III an unreal past condition, and mixed types combine aspects of both. Examples are provided for each type along with their typical structures. Other conditional expressions like "unless", "as long as", "so long as", "wish", and "even if"