| Past | Present | Future |
| Could was able to were | Can to be able to | shall be able to will |
| Might was allowed to were | May to be allowed to | shall be allowed to will |
| had to | Must have to | shall have to will |
82. a) Past Indefinite; 6) Future Indefinite :
He must pass the examination in anatomy.
He had to pass the examination in anatomy.
He will have to pass the examination in anatomy.
1. The students may take all necessary textbooks from the Institute library.
2. He can help you with your translation.
3. You must repeat the material of the lectures before the examination.
4. They cannot translate these articles without a dictionary.
5. He may not write out prescriptions.
.
1. The doctor says that you may walk.
2. The vitamins are substances which must be found in the diets of animals in order that they can utilize the organic foodstuffs to best advantage.
3. When the appetite is impaired and nausea and vomiting are common, meals must be small and be given at frequent intervals.
4. With the disappearance of symptoms the patient with infective hepatitis may leave his bed for purposes of toilet.
.
1. Did the doctor have to direct you to the X-ray examination?
2. As my sister has caught a bad cold she had to stay in bed.
3. Were you able to cope with the task which the teacher gave you some days ago?
4. Are you able to tell me what subjects the first-year curriculum includes?
5. You are allowed to use this equipment for your experiment.
6. Our district doctor will be able to go out to the calls in the afternoon.
7. My brother had to make an appointment with his doctor for 9 a.m.
8. Some first-year students are allowed to attend scientific circles.
9. Everybody has to keep the thermometer in the armpit for 10 minutes.
l0. He was able to take an active part in this discussion.
11.Are you allowed to go out shortly after such a difficult operation?
12. The patient had to wait for his district doctor in the waiting room.
13. The doctor was able to diagnose the disease instantly thanks to use of modern equipment.
14. We had been waiting for a long time before we were allowed to come into the room.
15. He was able to describe the properties of this substance.
16. Dr. N. had to operate without his assistants help.
| Dr West | may/might () must () cant ( , ...) | be writing () have written () have been writing - ( - ) | a new book. |
| A new book | be written - , have been written - | by Dr West. |
| Dr West | can/could (/ ) | write (, ) have written ( ) | a new book. |
| A new book | be written (, ) have been written ( ) | by Dr West. |
|
|
|
| Dr West | should ( ) should not ( / ) | write () (, ) have written () ( ) | a new book. |
| A new book | be written () (, ) have been written () ( ) |
85. : Perfect Active Infinitive, Perfect Passive Infinitive:
1. The onset of the infection was after 3 months of age, and the delay may have been related to the low infecting dose of the drug.
2. The doctor says that his patient could have lived without the muscle graft but that it has improved her quality of life.
3. One such event may have been the development of methods for the safe surgical removal of lung tissue.
4. The conflicting results might have resulted from the use of different enzymic methods.
5. These infants develop brain damage which may have passed unnoticed within the first months of life.
6. The substance found in the urine might have been derived from injured tissue.
7. It is a general principle that drugs should not be taken during pregnancy.
8. People with obesity could have been at risk from gallstones.
9. Changes in insulin receptors may have affected ageing.
10.Attention should have been given to the detection of growth regulators.
11. The recent publication could have been recommended to all students and research workers in the biological sciences.
12. There is a new group of drugs which might have affected the immune processes.
