The document discusses different types of conditionals in English grammar:
- The Zero Conditional uses the present simple tense in both clauses to talk about general truths.
- The First Conditional uses the present simple in the if-clause and will+infinitive in the main clause to talk about possible present or future situations.
- The Second Conditional uses the past simple in the if-clause and would+infinitive in the main clause to talk about unlikely or impossible present/future situations.
- The Third Conditional uses the past perfect simple in the if-clause and would+have+past participle in the main clause to talk about regrets about the past.
- Mixed Conditionals combine