How to use zero, 1st, 2nd and 3rd conditionals (if sentences)
There are four kinds of conditional sentences. The zero conditional describes real or specific situations, while unreal Conditionals describe unreal, imaginary situations or hopes for the future. With unreal conditionals there is a difference in the likelihood of them happening, however, they don’t refer to the past. The 3rd conditional is for past regret, how something could be different or a past hypothetical situation.
Conditional sentences are very useful structures in IELTS as they are seen by the examiner as complex sentences and are often included in a natural conversation. This comes in very handy in the IELTS speaking section when talking about your daily life, talking about possibilities and expressing regret or a hypothetical past.