Have to

NEED

SHOULD / OUGHT TO

MUST

	meaning	use	present	past
1.	obligation (speaker’s authority)	+?	They must provide us with all necessary data.	-
2.	necessity (speaker’s thought)	+	He must work hard to learn this computer language.	-
3.	prohibition	-	You mustn’t press any button.	-
4.	certainty	+	He must be working in the Internet. I can’t call him.	They must have already opened this file.

Notes:

1. Must has no other forms. To express past perfect infinitive can be used sometimes.

2. Had to is the past form of must which refers to a past obligation.

3. Need is used in its negative form to express the lack of necessity.

Упражнение 3. Прочтите и переведите следующие предложения, обращая внимание на значение модального глагола must либо его эквиваленты и форму инфинитива после них:

1. The data must have been lost. I don’t see it anywhere. 2. To use a CD-ROM, you must have a computer equipped with a CD-ROM drive. 3. You mustn’t interfere with the program work. 4. To read this graphics file you must have used a program that recognized the file’s format. 5. The user must create sample input data that represents every possible way to enter input.

	meaning	use	present	past
1.	advice (giving/asking for)	+ /? / -	Should these commands be carried out?	-
2.	obligation	+ / -	The files ought to be fully defined.	The PC shouldn’t have been used inappropriately.
3.	possibility	+	You should see the message on the screen.	They should have carried out the calculations.
4.	complaint	+ / -	You should be using another application for this purpose.	These devices should have been handled with great care.

Note:

Should/Ought to have no other forms. To express past perfect infinitive can be used sometimes.

Упражнение 4. Прочтите и переведите следующие предложения, обращая внимание на значение модальных глаголов should/ought to и форму инфинитива после них:

1. It determines which operations should be carried out and in what order. 2. They ought to have tested new applications. 3. Make sure your last command is finished. You should see the prompt on the screen. 4. The batteries should not be kept uncharged. 5. What kind of data ought to be typed?

	meaning	use	present	past
1.	necessity	+	To do this, you need to understand how the data bus width affects performance.	He needed to back up that file regulary.
2.	no obligation	-	You don’t need to use virus scanning every time.	You didn’t need to back up these files.

Notes:

1. Need can be used in different forms with and without “to” after it.

2. Needn’t and don’t need to are different.

- We generally use needn’t when the authority comes from the speaker and don’t need to when the authority doesn’t come from the speaker.

- To talk about the past, we use needn’t and Perfect Infinitive (means: you did but it wasn’t necessary) or didn’t need to.

Упражнение 5. Прочтите и переведите следующие предложения, обращая внимание на значение модального глагола need и форму инфинитива после него:

1. Most memory chips are now mounted on boards, you needn’t have checked for other ports. 2. Nonvolatile media are needed to store programs and data when the power is off. 3. The smaller size reduced the distance electrical signals needed to travel. 4. The fields need not be contiguous in memory, nor do they need to be part of a structure. 5. You can insert the executable code you need to “clean up” at an embed point.

	meaning	use	example
1.	necessity (circumstantial)	+ / -	You have to follow a number of rules when entering these commands.

Notes:

1. Have to can be used in all forms (present, past, future).

2. The difference between must and have to is that with must the speaker is giving his own feelings, while with have to he is just giving facts.

3. Mustn’t and don’t have to are completely different. “You mustn’t do something” means “it’s necessary that you do not do it”. When “you don’t have to do something” means “it is not necessary to do it; you don’t need to do it”.

Упражнение 6. Прочтите и переведите следующие предложения, обращая внимание на значение модального глагола have to и форму инфинитива после него:

1. You don’t have to push buttons; these actions occur under the direction of the program you are using. 2. If the program is designed to be sold commercially, the documentation will have to include directions for the user to install the program and begin working with it. 3. You have to remember which entity (set of fields) you described as “left” and which ones as “right”. 4. You won’t have to compete with other users to gain access to the system. 5. Because of its cost, new information had to be stored in appropriate archives and libraries for use by others.

Дата добавления: 2015-01-03