(modal verbs) , , , , , . can, must, have, be, may, might, need, would used to.
1. have be , (necessity). to. have must , :
He has to take extra measures to complete the test on time. | , . |
have , , :
But this new kind of fuel has to be handled very carefully. | . |
Our engineers had to solve many complicated practical problems to reduce wear in machinery. | , . |
I have to tell you something. | - . |
be , , , :
New program is to be implemented without delay. | . |
He is to meet the conference participants at the railway station. | . |
2. must , have, , .
An automobile must have gasoline to run. | . |
had to. must have . Must not , do not have , .
3. must (probability) (likelihood). , , + :
He must be very experienced engineer. He has been working for the company for many years. | . . |
4. must (probability), must have + past participle , , :
I did not see Boris at the meeting; he must have left early. | . , . |
Rigidity in this new structure must have been as essential as strength for bending under load may lead to a loss of control. | , , . |
5. can may , (ability) , + :
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The machine-tool can be stopped at any moment. | . |
6. may might , , . , (possibility) , , , , :
He may have got the capacitor he needed. | , , , . |
Might , may:
might have known that to cut down the flow of water in a pipe you need only to shut off a valve. | , . |
7. can could , , , , , , :
You couldnt have seen A380 jumbo jet in flight a couple of years ago. | A380 . |
He could not have overlooked such a serious mistake. | , . |
8. need want. need , :
You need not do it right now. | . |
9. ought (to) should, need , , , , , , , . . , , (advisability) , , :
They ought to have paid more attention to the problem of fuel consumption. | . |
This line should have been put into operation long ago. | . |
You need not have told him about that | . |
10. do , -. , :
Only at high temperature and pressure do silicon-based ceramics become appreciably affected by aqueous environments. | . |
do :
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The computer payroll system processes data with greater speed than the manual does. | , . |
11. used to would . , :
would work on his design for hours. | . |
would , :
Before, our plant used to buy the raw materials abroad. | Before, our plant would buy the raw materials abroad. |
would :
The chief engineer was ordered to apply the patent but he wouldnt do it. | , . |
would rather . Would rather + present tense would rather have + past tense past participle :
We would rather stay at a hotel than spend a night at the airport. | , . |
Carlos would rather have stayed home last night. | . |