When do I use have and have got?
Are "I have the answer" and "I've got the answer" both correct?
sounds more formal and somber, and it is often used as a statement of fact or as a direct response to the questions: Do you have the answer? Who has the answer? etc.
is more of an eureka moment remark, something one is likely to hear often in such a place as a college physics common room where students are bashing heads on seemingly intractable problems.
The have got construction is more of a Britishism. In the US, one would be more likely to hear:
"Have got" is certainly more informal. So if you never use "have got", you will be fine. However, if you want to use "have got", this is how it works.
Have and "have got" are sometimes interchangeable and sometimes not.
When have is being used as a modal verb (or helper verb), then you cannot use "have got".
When have is being used as a main verb, you can replace it with "have got", but only in the present tense.
This is true for possessive uses of have:
And also obligation:
Lastly, if you are constructing an imperative sentence, you can only use have:
A note on "have got" when referring to acquisition: this is not possible in US/Canadian English, where "have gotten" is the preferred form.
I have the answer and I've got the answer are both correct, yes. The latter is more colloquial and informal; avoid it in formal writing. Otherwise, use whatever sounds good to you at the time.