Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.

Example Input: I was writing something along '... I could only read upto page 34' when my spell-check app Grammarly complained that I should rather use 'up to'. So, what's the difference between the two and is there really any difference? Or is it that the condensation 'upto' is not technically allowed?.
Example Output: Upto is a misspelling of up to. -- Wiktionary Use up to with a space between the two words. Also, as Yosef Baskin says: You can use the following self-test: Does the single word say something different from the two words? If not, stay with two words. By contrast, into and onto do mean things other than in to and on to, so they work as single words.

Example Input: I'm looking for a word the describes the concluding text of a document, i.e. the opposite of the document's preamble. Is it just 'conclusion'?.
Example Output: Conclusion, afterword, and epilogue all seem to fit the bill. There's also postamble, but I believe that's more of a computer science term for data transactions.

Example Input: What is the difference between 'Did you find?' and 'Have you found?' When should I use the first sentence, and when the second one?.
Example Output:
Did you find is the simple past and indicates that you are no longer looking for it. Have you found is the present perfect and indicates a link with the present, specifically, that you could still be looking for it.