Given the Question and Answer pair, detect whether the answer is acceptable or not. Denote acceptable answer as "yes", otherwise denote as "no". An acceptable answer is consistent with the context in question, detailed, long, and uses general knowledge of English. Answers that are not definite and suggest a variety of options are not acceptable answers.

Question: Persistence and perseverance seem to have very similar definitions. Googling shows persistence: Firm or obstinate continuance in a course of action in spite of difficulty or opposition. perseverance: Steadfastness in doing something despite difficulty or delay in achieving success. What is the difference between them? 
Answer: "Persistence" is used in the sense of "stubborn" (obstinate). There could be a slight negative connotation. For example: The telemarketers persistently called us. We don't say they "perseverantly" called us. "Persistent" is used when there continuing action, and the purpose is either bad, or neutral, and sometimes(rarely) good. "Perseverance", is used when the purpose is good. That is, you're doing something to help someone, or to achieve a desirable goal, such as climbing Mt. Everest. Depending on how you feel on something, you could use "perseverance"/"Persistence". For example, the telemarketer calling you, could annoy you, and you could call him "obstinately persistent". But to the marketer, you might be to him, a tough customer, and he might seem to himself "bravely perseverant in trying to persuade this tough customer." As you can see, it gives a different "feel" about the thing described.
yes

Question: When a user wants to delete something on a website, I would like to display a message for him/her to confirm. Which of the following is the grammatically correct way to say so? Are you sure to delete this item? or Are you sure you want to delete this item? 
Answer: Are you sure to delete this item? Sure means "certain, without doubt". Therefore this asks if they are definitely going to delete the item. This isn't something to ask the user; if anything it's something for the user to ask about the program; "will it definitely be gone". Are you sure you want to delete this item? This asks not about what will happen (which is a question about the program) but what is desired (which is a question for the user). This is the one to go for.
yes

Question: I am referring to someone who makes people 'buy' what he says and gets things done by them through nothing but clever speech something one can describe as crafty or beguiling, but not fraudulent. I pondered over con man and con artist for a while but those terms seem to hold a hint of crime, so those terms won't fit in. I am wondering if there is a more suitable phrase or word. 
Answer: If you seek a definition with some connection to cult of personality I'd suggest "Svengali" and "Mesmerist." A bit obscure but they also provide some panache. It's also fun to make people look things up.

no