Question

How are you doing?

I'm fine. I'm okay. I'm good. I'm great.

I'm doing fine. I'm doing okay. I'm doing good. I'm doing great.
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Are the answers all fine?

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How is it going?
1. I'm terrible.
2. I'm not so good.
3. I'm pretty bad.
4. I'm awful.
5. I'm bad.
6. I'm so-so.
7. I'm very bad.
8. I'm not good.
9. I'm in bad condition.
10. I'm not in the mood.

(Are the responses all grammatical? Can we remove 'I'm' in all the sentences?)

Answer 1

In spoken, informal language, the "I'm" may be omitted. It's implied. All your responses are grammatically correct, if not formal "written" English. All are perfectly acceptable in colloquial, spoken language.