Prescriptive and disputed grammar
Although there is fairly general agreement about what you can and cannot say in standard English, there are a few 'grey areas' of DISPUTED usage where native speakers disagree. For example, can you or can you not say?
All of you will not understand.
Some people find this totally acceptable; others want to reword it as Not all of you will understand if that is what the meaning is, claiming that the original sentence 'really means' None of you will understand.
Other problems arise because of PRESCRTPTTVE rules, some of them dating from a time when people thought that English grammar should be like Latin grammar. These rules should not really apply to English at all, but many English people have heard them and (quite mistakenly) think it is wrong to break them. Examples of these doubtful rules:
Don't end a sentence with a preposition.
Say It's I. (Don't say It's me.)
Partly as a result of prescriptive rules, we often get HYPERCORRECTTON - which is people seriously misapplying a rule. Thus someone who has been told to say It's l may get the idea that me is somehow ungrammatical in any position, so they say *between you and I.
Another cause of disputed usage is natural change. Language changes all the time. People who notice changes often object to them and consider them wrong. (Perhaps in time between you and I will be generally acceptable.)
Exercise 1: Prescriptive rules, disputed usage and hypercorrection
Here are some authentic examples of modern English. Each sentence contains some kind of disputed usage - perhaps something that somebody would object to because it breaks a prescriptive rule, or a hypercorrection, or a newish development. Can you spot the problems?
1 I am impressed by the knowledge he and his friends show of different universities and courses ... They are tapped into a network of information. It did not used to be like that.
2 It would have ended in tragedy, if it hadn't have been for the courage of the victim. (Police officer speaking on television)
3 The doctor dismissed the symptoms and suggested she take up a relaxing hobby.
4 Q: What would you have been had you not been born a sportsman? A: I may have followed my father into the Services.
5 I wonder if he were indeed here yesterday.
6 As for we English, we should resist the temptation to make jokes.
7 The beautiful stallions were kept to one side of the route and us spectators were kept to the other.
8 Nearly four times as many girls in Britain suffer from asthma than in the 1970s - but all those who claim to be allergic are not suffering from it.
9 Poetry needs less words. (Playwright Alan Bennett, speaking on television about poetry and novels)
10 The carbon dioxide locks in the sun's heat, like glass locks heat into a greenhouse.
11 Writing my first rugby match report a feeling of unreality hit me.
12 The world can breathe a little easier after this historic summit.
13 You use a different sort of English in a Times leader than in a conversation in a pub.
14 If a regular customer were to make arrangements with their own branch, it may be possible to make arrangements for speedy clearance.
15 A salesman explained that the manuals included with most computers were hopeless. They either were impossible to understand, full of mistakes, or both.
16 None of the bodies so far recovered were wearing lifejackets.
17 Sartre had one of the best educations available to a man of his generation.
18 The idea seemed far too cruel to actually carry out.
19 No sooner are one set of perils surmounted than another lot, even more intractable, take their place.
20 The Prince tests some of the inventions, including the prototype of a sports car; plus there is a review of the most successful innovations in ten years of the awards.