This is an overview of the conditional that, I hope, will give you an overall appreciation for its complexity and your potential for being able to express nuanced ideas and opinions.
Facts and Generalities
The zero conditional is used when we talk about ideas or facts that are always, usually or sometimes true. There is a frequency to them and they are not a one off.
We use the simple present tense without any modals such as 'will' or 'might'.
If this happens, it always does that. CAUSE 🠊 EFFECT
If / when water reaches 100℃, it definitely boils.
If something goes up, it eventually comes down.
Real Present and Future
The first conditional is used when actions or events in the present and future are likely to happen or have an excellent chance of occurring. This refers to a specific event.
If this happens, I will / might do that. CAUSE 🠊 EFFECT
If I decide to come, I will / might / am going to meet you there.
I will / am going to text you tonight unless I am too busy. as long as I am not tired. I wake up. provided I have the time.
Unreal Present and Future
The second conditional refers to a situation that is unreal in the present or in the future.
If this happened, I would do that. CAUSE 🠊 EFFECT
If I weren’t so busy, I would call you , but I am quite busy, so, I am not going to call you.
The third conditional refers to situations in the past.
The past real conditional describes what would happen in real-life situations. The idea is that your habits have changed over time and you no longer do these things.
If this was the case, I used to do that. CAUSE 🠊 EFFECT
If the weather was nice, I usually went swimming at the beach.
I used to travel in summer if I wasn't able to find a part-time job.
The past unreal conditional describes imaginary situations in the past. You are talking about what you would have done differently if you had had the chance. It conveys the sense of regret.
If this had happened, I would have done that. CAUSE 🠊 EFFECT
Yesterday, if I had decided to go out, I would have called you, but I decided to stay home and read, so, I didn’t call you.