1. Examples of sentences:a) Phrasal modal: I’d be rather going to school every day than doing the cleaning in my room every single hour just as my mother asks me to do so.
b) Very simple example to understand what is a social use could be seen in the following sentence: This should work. While thinking of a more complex sentence, an example of “This should not overlap with your work schedule”.
c) The logical probability of a modal reflects a consequent reaction to something that was already said: I’d prefer to study mathematics if I fail in the history major this semester.
d) Frankly speaking, I would be able to join the discussion if I have to. For the moment, my schedule allows me such a luxury.
e) Would you be so kind to join us for the debate on Thursday night? We would appreciate your presence at the event, given your expertise and previous experience in the area discussed.
f) What are you ready to give away to obtain something different? Have you handed in your math assignment that you were given for homework last week?

2. Explain in the ambiguity of the following sentence in each of the following pairs:
a) a) It must be nighttime / It must have been nighttime
The first sentence uses a modal word, and there an addressee has to do whatever is indicated. The action that will have to be done would be carried out in the future. Contrary to the first sentence, one discusses the action that was already done in the past. Here, one can note that the modal verb conveys a presumption.
b) Will you help me with this problem? / Would you help me with this problem?
The first question expresses directly what one is asking. In the second question, the form that is conveyed with the modal verb “would” better reflects corruption which was meant to be used here.

I was able to go to the library last night. / I could have gone to the library last night.
In the first sentence, a modal verb conveys the fact of the possibility for an individual to go to the library last night. However, the context indicates that an individual could do so, but it’s unclear whether he went there. A similar case applies to the second sentence. An individual had an opportunity to go to the library (an indication goes to the past), but we also don’t know if he went.

C) The ground is wet. It may have rained last night. / The ground is wet. It must have rained last night.
The first sentence indicates not such a strong presumption of the fact what happened whereas the second sentence clearly states that it was raining last night.

D) You should do your homework. / You had better do your homework
The first sentence indicates a suggestion; the second sentence is about the necessity to do your homework.

2-Explain any differences between the following sentences to student who is confused weather one is more accurate
First of all, the second sentence is much more precise than the first one. It specifies the purpose of going to Spain. However, in the first sentence, one can note the intentions of an individual, conveyed by the form “going to”.

3- Compare and contrast the following pair of sentences:
a) The first sentence is used in past simple whereas the second refers to present perfect.
B) John repairs cars on the daily basis; Jon is currently repairing the car.
C) A person recently wrote a biology paper; a person has written multiple biology papers recently
d) It is an obligation to call her; there is a suggestion to call her
e) There is a presumption that it is important; there is a denial of the importance of the fact

C) Explain the nature of the error and suggest corrections:
A) two modal verbs are used; only one is possible
b) a wrong modal verb for the form of politeness is used
c) after using should we do not use “to.”