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.

Coming from a technical background I'm slightly confused. What is the difference between simultaneously and concurrently? How do we use these words?.
I just looked these up in an online dictionary; this is what I found: concurrently: overlapping in duration simultaneously: at the same instant Both of them mean 'at the same time,' and are almost interchangeable. That said, if I had to point out a slight difference, I'd say that concurrently occurs over a longer time, and is a bit less synchronized than simultaneously. For example: The two processors were running concurrently, then they crashed simultaneously. In that example, I wouldn't swap the two words in question.

I want to ask whether I can use the word 'Fuck' in a formal context. Apparently, the word dates back to the early 16th century, so it shouldn't be considered slang (although, it is misused as slang for other reasons), but regardless of its vulgarity, could I use it in a formal context with its original definition? I imagine that people will be surprised, but when realizing in what context I am using it in, then it will be more understandable and acceptable to use it. Firstly, I do not even know the definition of the word due to its vastness in meaning, I always thought it was an exclamation-like word meaning nothing (for it to mean sexual activities is a slang definition, is that not correct?), but used purely for emphasis. What does it first and foremost mean in its original/accurate and/or formal definition? I also know of another definition of the word 'Fuck,' which is 'I will fuck you' as in 'I will defeat you' (in context of fighting or combat), is that a formal definition as well? I mainly ask for this, because I need to use the word in this context, specifically and especially. Also, side question, is it possible not to always make it a vulgar word? Thanks in advance.
Let's just go ahead and say, no. It's questionable to use expletives here, so... unless you're writing a dissertation on the usage of the word in question, again: no. You shouldn't use any word you don't know the definition of, but here at Stack Exchange you may use them to talk about them. They are permissible when they are the context.

Opening doors, offering to pay the tab, helping with a coat or a light of the smoke: we may describe these acts of a man to be gentlemanly. In a word, how may we describe these acts of any person?.

I'd go with courteous, the etymology of which also hints at a closer fit to gentlemanly than, say, decorous, polite, or respectful.