Anonymous  +  736040 Mon, 18 May 09 03:13 PM Dear teachers   when I mention the event that happend in the past by using "may" or "can",   what's the difference in meaning betewen "I might do" and "I may have done" /                                                               "I could do" and "I can have done"  ?   thank you in advance.     Anonymous

	AlpheccaStars  +  736204 Mon, 18 May 09 05:04 PM "I might do it"  - The event of doing it is in the future, and you are still considering if you will do it or not. "I may have done it"  The event of doing it is in the past, and you cannot remember if you did it or not. "I could do it"-  You have the ability to do it.  This is frequently used with an if-clause: I could do it if I wanted to. I could do it, if I had the proper tools. "I can have done"   - not grammatically correct.  "could" is used with the past perfect subjunctive in this example: I could have done it, if I had had the proper tools. AlpheccaStars Joined on Sun, Oct 12 2008 Senior Member 3,508 The pen is mightier than the sword. Edward Bulwer-Lytton (1803-1873) Clauses, Past Perfect, Subjunctives, Past Tenses, Writing

	Fandorin  +  736240 Mon, 18 May 09 05:24 PM If Alphecca doesn't mind, I'll give my pitch too. Can +Perfect Infinitive can be used in Negative and Questions when one doesn't believe something happened or turns down the possibility it happened. Frankly, I haven't seen it for a long time and suppose it's obsolete in modern English. John can't have done it. He is so kind. Can he have said it? (How on the earth is it possible? I refuse to believe that). Fandorin Joined on Thu, Dec 20 2007 Moscow Contributing Member 1,384 Whatever happens, be yourself. Negatives, Countries, United Kingdom, Great Britain, Languages

	AlpheccaStars  +  736287 Mon, 18 May 09 05:58 PM Thanks for the additional info, Fandorin. The form you quote must be obsolete, because I have not seen it. Today we say: John couldn't have done it. It's not like him. He is so kind. Could he have said it? (How on the earth is it possible? I refuse to believe that). AlpheccaStars

	Mister Micawber  +  931613 Wed, 07 Oct 09 08:21 AM Correct where?  They all have their correct uses. Mister Micawber Joined on Wed, Aug 4 2004 Yokohama Veteran Member 30,825 'The question is,' said Humpty Dumpty, 'which is to be master-- that's all.'