I'll carry it for you/I'm going to carry it for you

[niue]

Q1. Which is the most commonly used after "My suitcase is very heavy."?
1. "I’ll carry it for you."
2. "I’m carrying it for you."
3. "I’m going to carry it for you."

Q2. Which is the most commonly used after "Daniel called while you were out."?
1. "OK. I’ll call him back."
2. "OK. I’m calling him back."
3. "OK. I’m going to call him back."


Q3. Which is the most commonly used after "Daniel called while you were out."?
1. "Yes, I know. I’ll call him back."
2. "Yes, I know. I’m calling him back."
3. "Yes, I know. I’m going to call him back."


Thanks in advance.

 

[5jj]

Q1. Which is the most commonly used after "My suitcase is very heavy(no period)"?

That is not an easy question to answer. A better question would be "Which is the most natural to use after ...?"

1. "I’ll carry it for you."
2. "I’m carrying it for you."
3. "I’m going to carry it for you."

The offer expressed by #1 is the most natural.

Please ask only one question at a time. When you are happy with the response(s) you receive, you can submit follow-up questions.

 

[niue]

Thank you for your answer and advice.
I agree with you that #1 is the most natural for Q1.

Let me ask you the second question.

Q2. Which is the most natural after "Daniel called while you were out"?

1. "OK. I’ll call him back."
2. "OK. I’m calling him back."
3. "OK. I’m going to call him back."

Thanks in advance.

 

[Barque]

The first again.

 

[Skrej]

Your whole thread really seems to be a question about the difference between 'will' and 'going to'.

There isn't a 100% iron-clad rule on this, but we generally tend to use 'will' for promises/threats/offers, personal belief-based predictions, and spur-of-the-moment decisions. We typically reserve 'going to' for previously made plans, imminent events, or evidence-based predictions (like a weather forecast).

You can already see that there's overlap for something like a prediction, and nobody's going to give your word choice a second thought regardless of which you pick for predictions.

Going by these rough guidelines, you can see why 'will' is the more natural choice in all three of your scenarios. "Going to" is certainly possible with the right context, but the present continuous, while again not entirely impossible, is the third least likely.

 

[niue]

Thank you for your explanation.
Then, the anwer for my question #3 would be the first choice again.

Let me explain why I posted the above questions #2 and #3.
I read the following in a grammar book.

UNIT 22 ''I will' and 'I'm going to''

A 'Future actions'

will ('ll): We use will when we decide to do something at the time of speaking.
going to: We use (be) going to when we have already decided to do something.

Compare:
- "Daniel called while you were out." "OK. I’ll call him back."
But
- "Daniel called while you were out." "Yes, I know. I’m going to call him back."

[Source]
Title: Grammar in Use Intermediate (by Raymond Murphy)
Publisher: Cambridge University

After reading the above, I wanted to be sure whether you native speakers comply with the above usage rules actually.

 

[5jj]

I wanted to be sure whether you native speakers comply with the above usage rules actually.

Think of them as general guidelines as to how these forms are often used. They are not fixed rules.

 

[Skrej]

will ('ll): We use will when we decide to do something at the time of speaking.
going to: We use (be) going to when we have already decided to do something.

Compare:
- "Daniel called while you were out." "OK. I’ll call him back." This was the first time hearing about the missed call. There's no prior knowledge of the call, so it's a spontaneous decision to return the call. You could also consider it a promise to the speaker that you'll return the call. Either way, 'will' still follows the guidelines.
But
- "Daniel called while you were out." "Yes, I know. I’m going to call him back." The speaker already knew about the missed call, and had already made plans to return the call when he or she gets a chance.

The examples from the text still follow those general guidelines, though. See comments in blue above.

It's possible the speaker had only found out about the missed call a few minutes ago, before being informed of it a second time (or maybe even multiple times). The speaker may have made those plans to return the call only a few minutes ago, but it's still a prior plan. There's no fixed time limit of how far in the past the plans had to have been previously made to justify using 'going to'.

You can see there are a lot of possibilities in context, as well as ways to justify a choice of 'will' over 'going to'. That's why they're just guidelines, not hard and fast absolutes. Native speakers do follow them, but it's just that the guidelines allow a lot of flexibility in application.

Because of that, it's going to be very unlikely that misuse will create significant comprehension problems. It might strike a native speaker as an odd choice, but they're not going to be wondering what you actually mean.

I don't dwell on it very long when I cover it with my students. Of all the possible errors they could potentially make, mixing up 'will' with 'going to' is pretty low down my list of concerns.