Modal Verb. I Created only one Yest but bulk of Explanation, I hope You'll Like it. Thank you!
TEST: Sorry, I have no time to discuss anything. I _______________ be at work at 10 o'clock.
may
could
can
must
Correct Modal Verb to use: 4.mustExplanation:
For this test sentence we are given four modal verbs to choose: ‘may’, ‘can/could’ and ‘must’.We use ‘may’ in affirmative sentences when we are not sure about something and when we refer to weak possibility in the present and future: Our grand-children may be coming to see us at weekends.We often use ‘can’ to talk about someone’s skill or general abilities. This is something that once you have learnt you can do any time you want, like being able to read or swim or drive a car, for example: I can sing songs in English.We use could as the past tense of can to express a variety of meanings: (1) to talk about past ability:She could run very fast when she was young.; (2) to say that something was possible or impossible:Sometimes it could be very cold in winter in Russia.; (3) to express possibility in the present and the future: This cake could be tasty. (= I am not certain that it is tasty.)The modal verb ‘must’ can express ‘strong obligation and necessity’: I must talk to you about the new article.The context of the test sentence ‘Sorry, I have no time to discuss anything. I _______________ be at work at 10 o'clock.’ is connected with work obligations – something that we do because it is our duty(something that we do as part of our job or because of our position). The speaker has a job duty to be at work at 10 o’clock. Thus, among all the given modal verbs only ‘must’ expresses an obligation and we are to choose ANSWER 4.