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.

Possible Duplicate: What is the difference between a phrase and a clause? Can you give me an easy description of the differences in meaning between clause, phrase, and sentence?.
Phrase, clause and sentence are three of the structural units that create meaning. A phrase is a word or words that don't have much meaning on their own. If I suddenly utter the phrase My brother, you'll wonder why I said it, but if I say My brother drives, you'll feel I've said something that has meaning. There's a completeness about it, because it contains the verb drives. That makes it a clause, but it is also a sentence. But I needn't stop there. I can go on to say something else, almost without drawing breath. I can say My brother drives, but he doesn't drive very well. I've added another clause, and together they, too, make a sentence, joined by the little word but. It is perhaps helpful to see two or more clauses joined together as a clause complex, although sentence in general use describes both single and multiple clauses.

Possible Duplicate: 'Nikki's and Alice's X' vs. 'Nikki and Alice's X' Consider describing the wedding of X and Y. If I want to avoid the overly-formal and poor-flowing 'wedding of', it is more correct to say 'X and Y's wedding' or 'X's and Y's wedding'? I acknowledge a very similar question has already been asked: What possessive forms are used for mutual 1st person ownership? But unfortunately the example given is able to be easily phrased a different way and so respondents have been able to get away with avoiding the direct question. Let's face it, we come across the need to get across the concept of mutual possession all the time and we don't always want to have to resort to the more tortured 'Z of X and Y' as with the French language. NB: In some cases, people get around this problem by dropping the apostrophes altogether and 'adjectivising' the owners, especially if the owners are actually plural entities themselves. Eg. The 'Mazda and Mitsubishi combined outputs' instead of the 'Mazda's and Mitsubishi's combined outputs'. Let's not let this muddy the waters though.
This site states it very well: A less-often faced decision involves the use of apostrophes where multiple owners are named. Where two or more people own one item together, place an apostrophe before an 's' only after the second-named person. For example: Incorrect: Bill's and Mary's car was a lemon, leading them to seek rescission of their contract under the state's lemon law. Correct: Bill and Mary's car was a lemon, leading them to seek rescission of their contract under the state's lemon law. However, when two or more people own two or more items separately, each individual's name should take the possessive form. For example: Incorrect: Joanne and Todd's cars were bought from the same dealer; both proved useless, even though Joanne's car was an import and Todd's was a domestic model. Correct: Joanne's and Todd's cars were bought from the same dealer; both proved useless, even though Joanne's car was an import and Todd's was a domestic model. ('The Legal Writing Teaching Assistant: The Law Student's Guide to Good Writing', by Marc A. Grinker) So, saying 'X's and Y's weddings' (note that it's weddings not wedding) has a different meaning from 'X and Y's wedding'. The first one is denoting two separate weddings, and the two subjects named are not getting married to one another, but the second one is the one you are probably trying to say.

When should whilst be used instead of while? For example, should I use the first or the second sentence? They don't do this whilst they do that. They don't do this while they do that. Which would be correct?.

I believe while and whilst are interchangeable, but whilst is more archaic and adds a nice flavoring to the sentence. That being said, 'whilst' doesn't seem to come up so often in the middle of a sentence as you had it there, so I would use 'while' in that case, even though both are grammatically correct. Whilst seems more apt to be put at the beginnings of sentences, e.g. Whilst going about my merry way I chanced upon a vagabond. Taking this serendipitous opportunity to satiate my bloodlust I decapitated him with a fork.

