Objective
Clarify the context(s) that can affect which one to use.
Background
Continuation of "Ir a" versus future tense when asking a question
Question
Although the previous thread suggests both will be the same, it seems to me there can be a difference.
I feel 'ir + a' suggests a situation where the future event is highly probable, or it is logically to happen. Such as when to day:
- It is very cloudy and getting dark. It is going to rain.
- The meteorological agency said it was going to rain (because they had data and did calculation)
Whereas it seems to me the future tense suggests a possibility that it can/may happen but no solid basis.
- A comet may/can crash into the earth within 500 years.
- I have a desire to live abroad. I can be in other countries when I graduate.
If these stand, then I suppose the difference can be:
¿Cuándo va a venir? suggests that there is a reason or an arrangement that a person should come and asking when they will.
¿Cuándo vendrá? suggests someone may come or may not come, but to ask when they may come if they do.
Are these correct?
Thanks in advance