There is no legal limit on how much of a book or an article or other source you can use in writing an essay or a paper. There is a legal doctrine, the doctrine of fair use, that allows you to use someone else’s copyrighted material to some degree. What really matters is how you are using the material that you are quoting. If you do use two or three paragraphs, you will need to be sure to put the entire passage in quotes so that it is clear that you are not claiming that the work is yours. You will also need to cite your source. This is the minimum requirement. Most teachers, however, will very much prefer that you not simply quote that much of a copyrighted work verbatim.
As I mentioned above, the way that you are using the material matters. Let us say, for example, that you are doing a review or a critique of a novel. In that context, you might copy two or three paragraphs so that you can really show something like how the author is using language over an extended portion of the work. On the other hand, let us say that you reviewing a novel and you want to use two or three paragraphs of someone else’s review of that same novel. Your teacher is much less likely to approve of this. They are much more likely to think that you should do your own work and come up with your own ideas. This might not be a legal violation of copyright, but it would probably hurt your grade.
To summarize, there is no set legal limit on the length of a quote from a copyrighted source. It is very unlikely that two or three paragraphs quoted in an academic paper would exceed legal limitations on fair use. However, your instructor is likely to take points off if you use such a long quote in most situations. It is better to make the quote as short as possible and to put more of your own words in your essay or paper.
As far as I am aware, as long as you give credit to the particular source(s) you can include two or three paragraphs. However, in my experience as a student, I agree with the previous response "your instructor is likely to take points off if you use such a long quote in most situations. It is better to make the quote as short as possible and to put more of your own words in your essay or paper". Paraphrasing the quotes in your own words is also a good option but you must still give credit to the source.. I'm posting a link that I find very helpful with referencing and quoting etc. Hope it's helpful!