MAY – to be allowed (permitted) to do smth

CAN – be able to do smth. / be capable of doing smth.

	meaning	use	present	past
1.	physical or mental ability or possibility	+ -?	You can use computer for various purposes.	We couldn’t use the floppy because of the viruses.
2.	permission	+	You can try a new application for this task.	-
3.	suggestions	+	We can/could try another procedure instead.	-
4.	offer	?	Can I offer you this new product of IBM?	-
5.	polite request	?	Can/Could you help me with the database?	-
6.	surprise or astonishment	?	Can/Could you make such an inquiry?	How can/could you have entered this data?
7.	doubt or uncertainty	-	-	The processor can’t/couldn’t have come to a halt.
8.	certainty	-	They can’t/couldn’t be	They can’t/couldn’t have been
9.	prohibition	-	We can’t get access.	They couldn’t use that devise.
10.	lost opportunity or complaint	+	-	The floppy could at least have been checked for viruses before.

Notes:

1. Can has only two tense forms: can (present) and could (past), so for other tenses to be able to do smth. or to be capable of doing smth. are used. But if you mean that someone managed to do something in one particular situation (where can or could are possible), you have to use was/were able to do smth. or was/were capable of doing smth.

2. Could is not always the past of can, sometimes it has a present or future meaning. Perfect infinitive after can or could in such cases shows that they refer to the past.

3. Passive and progressive infinitives after can or could are also possible in some cases.

Упражнение 1. Прочтите и переведите следующие предложения, обращая внимание на значение модального глагола can либо его эквиваленты и форму инфинитива после них:

1. You can end your program with ‘quit’ command. 2. The information from memory can be retrieved by CPU. 3. We will be able to correct the arrows in the program. 4. Couldn’t the transistors or other radio elements be joined together right inside the crystal? 5. Engineers could thus substitute program code words for hardware parts. 6. Couldn’t they have created this program by themselves? 7. The computer memory can be considered as consisting of a number of cells capable of storing binary patterns representing program instructions or data. 8. He wasn’t able to perform those calculations without a computer. 9. In one program run, memory cells 5 and 6 could have been set to 70 and 25, respectively. 10. The sequence couldn’t have been chosen wrongly.

	meaning	use	present	past
1.	permission	+ /?	You may use my ISP if you wish.	-
2.	prohibition	-	You may not use my e-mail box.	-
3.	possibility	+ / -	It may/might be a faulty program.	The modem may/might not have been switched on.
4.	suggestion	+	We might use other graphical software.	-
5.	complaint	+	They might pay more attention to the instructions.	He might have checked his e-mail at least sometimes.

Notes:

1. May has only two tense forms: may (present) and might (past), so for other tenses to be allowed (permitted) to do sth. is used.

2. Might is not always the past of may, sometimes it has a present or future meaning. Perfect infinitive after may or might in such cases shows that they refer to the past.

3. Passive and progressive infinitives after may or might are also possible in some cases.

Упражнение 2. Прочтите и переведите следующие предложения, обращая внимание на значение модального глагола may либо его эквиваленты и форму инфинитива после них:

1. This device may not be switched on here. 2. At first the desktop might seem a little foreign to you. 3. It’s also more installation procedures than you might expect. 4. Will she be allowed to process these figures? 5. It may have beensaid that the development of modern computers was entirely depended upon developments in integrated circuits. 6. Different combinations of 1s and 0s may be used to represent numbers and characters (letters of the alphabet special characters). 7. Were they allowed to operate that new device? 8. Programs other than the one that is being obeyed may be stored on a backing-store external to the computer memory. 9. You may not be the only person using the program and this is the factor to be considered. 10. Combining both of these technologies might produce a completely new range of possibilities for user of information technology.

Дата добавления: 2015-01-03