Hypothesis

.hypothesis: y-ai po-'pa: the-@e  si-si

Enormous Astronauts went universe to confirm the hypothesis.

本来要做但没做

. would have done (it means as usual logic, it will happen. But actually it won't happen)

I would have passed the exam if I have tried a little hard.

.wouldn't have done

Without your help, I wouldn't have achieved so much.

. could have done ( it mean you can do it as usual)

I could have finished it on time without your disturbance.

Normal(more possibility)

. if ..., sb will/can ...

if I go to work on time, I will/can improve my reputation and reduce the loss of money.

.( plan to, want to，would like to)

  If I have time, I intent to do more design job.

Detail:

1. 一般通俗的情况

less realistic

. If sb did ..., sb would/could/might do ...

  If I had less work, I'd travel more.

. is were not was

If I were you, I'd do a course in programming.

Detail:

1. 自身的特殊情况

2. contrary to the present situation

Unrealistic

1. If sb had done, sb would have done

  If I have finished my study, I would have achieve master degree.

If I had quited school, I wouldn't have been so successful.

Detail:

1. Contrary to the past situation

2. express regret

Contrary to the future situation 

Shap:

. If s + should + v原型，s + could/ can + v

Apply:

If it sprinkles, I'll open my umbrella.

Detail:

. 万一，与pure condition 如果不一样

Contrary to the truth

Shape:

If s were to v(simple), s + should/... + do

Wish

shape

. S wish + clause

图片发自App