I have heard instructions given in a friendly and encouraging tone: "Do as much as you could," instead of the correct: "Do as much as you can."Why is it incorrect? Because the sentence begins in the present tense–"Do"–and should correctly be followed by the present tense "can."On the other hand, in the sentence "You did as much as you could," "could" is used correctly here following on the past tense "did.""So much for can and could. The same sequencing is needed when using may (present tense) and might (past tense), eg "I think I might attend the concert," is incorrect and should read instead: "I think I may attend the concert," or "I thought I might attend that concert."On the subject of can and may, I may as well deal with the difference in their meaning, as many people have asked me what it is:May I? and Can I?
Lucky you that you did not have to learn it by being told, in answer to your "Can I go to the cinema?" "Yes, of course you can walk to the cinema with your friends this afternoon"–meaning you are able to; you have two strong legs to get you there, but–here comes the catch: "You may not. You are not allowed to do so; you haven't my permission to go, not only because your grammar is so poor, but you have not done your chores."So, now you know. You can, but you may not.Trust me, many of us learned this the hard way. Try teaching it cleverly, but kindly, to your children. They won't easily forget the difference.There is another rule regarding sequencing verb tenses that I would like to stress. At times, when one begins a sentence in the present tense, one may move to the future tense.If, on the other hand, one begins in the past tense, one must continue in the past."I know (present) that you will (future) succeed.""I knew (past) that you would (past) succeed."This also tests your understanding of the "will" and "would" problem that we face each day.
Putting direct speech into reported speech is another testing ground for the sequence of tenses.He said to me, "I hope you will be able to attend the meeting this afternoon." Is changed in reported speech to:He hoped that I would be able to attend the meeting that afternoon.He believes you will agree is changed to He believed that you would agree.I keep persisting with the will/would difference because it is not only said incorrectly, but written and printed incorrectly, regardless of the circumstances. Not long ago, I sat through a lengthy service, and had time to read and re-read the printed programme distributed to the large audience with the offending "would" instead of "will" and vice versa appearing not once but twice in the recorded history and future hopes of the event.
It bothered me that that specially printed programme, with its ornate colourful graphics and stylish lettering, included in the text the offending "would" and "will" that were missed (twice)."Will" is definite, not a wish or request. The correct version would have been "I would like some help."He continued, "I hope that they would now listen to my pleas."Poor sequence of tenses. Correction: "I hope that they will now listen to my pleas"–present tense followed by the future.Too many people, especially those who are trusted, expected and relied upon by clients to oversee printed material are careless about simple English rules that may detract from the message being conveyed, and, in extreme circumstances, even ruin a person's chances of being taken seriously.Nevertheless, it is not too late to learn and to pass on the knowledge–in keeping with the inspiring Chinese saying, "It is better to light one little candle than to curse the darkness."