will vs. be going to

[Heidi]

Dear teachers,

In the following situation, I would like to know if you prefer to use #1 or #2?

#1 He is going to fall into the hole.
#2 He will fall into the hole.
Situation: A man can't see where he's going, because he's carrying a big box. There is a hole in front of him. What is going to happen?

[Nannou]

Dear teachers,

In the following situation, I would like to know if you prefer to use #1 or #2?

#1 He is going to fall into the hole.
#2 He will fall into the hall.
Situation: A man can't see where he's going, because he's carrying a big box. There is a hole in front of him. What is going to happen?

I think that both are correct and possible.
Will / going to express an action that will occur in the future or an intention/future plan (though the action in your example is not intentional at all.

I will study journalism after my baccalaureate.
I'm going to study journalism after my baacalaureate.
I intend to study journalism after my baccalaureate.
I'm thinking of studying journalism after my baccalaureate.
= all of the four sentences express a future plan.

[Heidi]

I think that both are correct and possible.
Will / going to express an action that will occur in the future or an intention/future plan (though the action in your example is not intentional at all.

Dear Nannou,

A grammar book of mine says that if we can see the situation now, when making prediction, we use 'going to', not 'will'. For example,
"Look at those black clouds, it's going to rain." (not 'It will rain').
Is this rule still common today?

[Nannou]

Dear Nannou,

A grammar book of mine says that if we can see the situation now, when making prediction, we use 'going to', not 'will'. For example,
"Look at those black clouds, it's going to rain." (not 'It will rain').
Is this rule still common today?

Then, it seems that you know the answer.

[Heidi]

Then, it seems that you know the answer.

Dear Nannou,
No! not really. I get confused. Because another book says that there is no difference in meaning between #1 and #2.
#1 According to the weather report, it is going to be cloudy tomorrow.
#2 According to the weather report, it will be cloudy tomorrow.

I would like to know what most people would say.