Using 'to be going to do something' instead of future simple ('will')

Question

In Oxford English Grammar Course by Michael Swan & Catherine Walter (OUP 2011) I have come across the following example:

Jennifer's eight, and she doesn't know what she's going to do. One day she says she's going to be a dancer, and the next she says she's going to work with animals.

In the place of the person describing Jennifer I'd say:

One day she says she'll be a dancer, and the next she says she wants to work with animals.

My point is that we use 'to be going to do something' when we have already decided to do something and one day doesn't seem as enough time to make a decision.

Am I wrong?

Answer 1

Jennifer's eight, and she doesn't know what she's going to do. One day she says she's going to be a dancer, and the next she says she's going to work with animals.

I don't think that the construction going to carries with it a sense of determination so steadfast that one cannot change one's decision the next day. A child is especially likely to change their decision on a whim.

This construction is a bit informal. Yes, it used to express an intention, to talk about plans, but that alone does not imply that the intention or the plan is the product of a thorough reflection.

Michael Swan makes a comparison between going to and the future-time use of the Present Progressive in his Practical English Usage, topic 214.2. What he says is that

.. we prefer going to when we are talking not about fixed arrangements, but about intentions and decisions. Compare:
I'm seeing Paul tonight (emphasis on arrangement)
I'm really going to tell him what I think of him (emphasis on intention)

If we say

One day she says she'll be a dancer

The clause no longer stresses her intention, but allows for some variation: it could be that the girl's parents planned for her to be a dancer and already enrolled her in some dance training group.

If we say

she says she wants to work with animals

The clause no longer stresses that she has plans to work with animals, and allows for some variation again: it could be that she has a long-term plan overriding her desire to work with animals ("but I think I'd better be a molecular biologist, like my Mom"). Or maybe she wants to work with animals, but is not yet sure if she is going to do so when she grows up.

Answer 2

Both 'will' and 'to be going to' are correct in these phrases. They are both referring to a future action.

While 'will' is sometimes used to enforce more certainty and determination ("I will do that"), both of those phrases are correct and either could be used.

we use 'to be going to do something' when we have already decided to do something

This isn't correct. Decision to do something has nothing to do with which phrase to use. Now, sometimes people have preferences or habits for when they use one phrase or the other, but the truth is, that will simply come with time listening and speaking, and it doesn't matter really which you use.

Answer 3

The OP thinks that we use "to be going to do" when we have already decided to do something", but I think the other way around. We usually use "will" when we have decided to do something, whereas we usually use "to be going to do" when we intend or have a plan in existence to do something. Moreover, the use of the "to be going to do" is more informal and common in conversation than the use of "will".

So the use of "to be going to be/work is more appropriate in the statement presented.

Answer 4

There are two things you got wrong with your analysis that are unrelated to the choice between "will" and "be going to":

1. The person is stating what Jennifer said

When you state what someone else says, you are stating what they actually said, not what you believe they should have said. Even if Jennifer hadn't decided, if she said she did, then it'd be wrong to paraphrase

Jennifer: "I have decided"

as

Jennifer said she hadn't really decided yet.

(Unless you're using the word "say" in a metaphorical sense, to mean something different from what it usually means.)

2. Jennifer might have actually decided

Have you ever heard of a "split-second decision"? People can decide quickly, without much deliberation. And deciding does not mean that you can't change your mind later.

You might wonder, how could Jennifer have decided, if the writer states that "she doesn't know what she's going to do"? The writer might be wrong. But even if they're not wrong, deciding is not the same as knowing the future, unless you are omnipotent. Consider the following sentences:

I made my decision, but I don't know if it was the right one.

I decided, but I might change my mind.

Don't mix grammar and semantics

Sometimes people can fall into a trap of trying to match rules of grammar (or rules of thumb) too closely to objective truths of the world being referred to. That's not how language works — language is for expression. The correct usage of language follows what is to be expressed.

Answer 5

Totally the same and totally interchangeable. There's no different shades of meaning. "Will do" is precisely the same as "going to do."