What are conditionals sentences in English grammar? Sometimes we call them 'if clauses'. They describe the result of something that might happen (in the present or future) or might have happened but didn't (in the past) . They are made using different English verb tenses. There are four kinds: The Zero Conditional: (if + present simple, ... present simple) If you heat water to 100 degrees, it boils. The First Conditional: (if + present simple, ... will + infinitive) If it rains tomorrow, we'll go to the cinema. The Second Conditional: (if + past simple, ... would + infinitive) If I had a lot of money, I would travel around the world. The Third Conditional (if + past perfect, ... would + have + past participle) If I had gone to bed early, I would have caught the train.