TASK DEFINITION: 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.
PROBLEM: I'm wondering which one of these expressions is correct? This stuff or these stuff?.

SOLUTION: Stuff is a collective noun it represents a group of objects. Just as one would say 'this group' or 'this pile,' one would say 'this stuff'.

PROBLEM: What's the difference between everytime and every time? I'm a little confused about them, they both seem to have same meaning. Excluding their spelling, are there any other differences between them?.

SOLUTION: The difference is that 'everytime' is not a word, and 'every time' means all occurrences: 'Every time I go to the beach, I get a sunburn.' You may be thinking of the difference between 'everyday' and 'every day.' The former is an adjective that can mean either daily or ordinary and common, and the latter is an adverb meaning each day: 'I don't have any fancy clothes. I wear everyday clothes every day.'

PROBLEM: I'm looking for a short word that could describe people who are always going to every event in town. It doesn't need to be an existing word, feel free to create one of your own. It can also be made of words related to events and parties. (ex: club, event, guest list, etc.) Edit The word will serve as a new term to describ these people in a favorable way. It will probably be used for an app name so it need to be catchy and fun. ( Preferably ).

SOLUTION:
You may be looking for socialite: someone who is well-known in fashionable society and is often seen at parties and other social events for wealthy people (Merriam-Webster)