1) Monday should be fine.
2) Monday would be fine.
Should in sentence 1 is not the same use of should that we find in examples such as:
- What should I do?
- You should apologise.
- You should eat five portions of fruit and vegetables every day.
The sentences above are asking for advice or giving advice. We can think of advice here like a form of weak obligation. If someone gives us advice, there is some pressure on us to do that thing - but we don't have to do it - it is our decision. This kind of meaning, when we talk about obligation and permission, is called DEONTIC modality.
Sentence 1 is NOT about deontic modality. This type of should is about EPISTEMIC modality. Epistemic modality is about knowledge and belief. Think about the following sentences:
- It might be in box 3.
- It should be in box 3.
- It must be in box 3.
The first example above shows that the speaker has a weak belief that it is in box 3. The second sentence shows that the speaker has a fairly strong belief that it is box 3, but she's not certain. The last example shows that the speaker is certain that it is in box 3.
In the Original Poster's example, (1) indicates that the speaker has a strong conviction, a strong belief, that Monday will be fine. Of course this is the technical meaning of what they are saying. The effect of saying this sentence is probably "Yes, choose Monday".
Would in sentence (2) indicates a logical result of choosing Monday. The sentence is like the last part of a conditional:
- If you chose Monday, Monday would be fine.
Here the speaker is definite about the fact that the result of choosing Monday is it's being fine. They aren't indicating any doubt about it. Again the effect in the conversation is probably "Yes, choose Monday".
Hope this is helpful!
This is quite a nice answer to your question.
In response to your first question, here's what I would say:
How do you know? - How does the person know the information (present)
How did you know? - How did the person know the information (past)
The above examples mean the same thing, just one is in the present and one is asking about the past.
How would you know? - Probably used in a response/remark, e.g:
A. I think you stole the money
B. How would you know?
You can see in answer B that you can put the stress on would or you, to differ the meaning. E.g:
How would you know? - Asking how the person would know the information
How would you know? - Asking how the person in particular would know
Overall, the difference between do and would in this context is:
How do you know? - this is used when wondering how someone found out: e.g:
A. I know you stole the money B. How do you know?
As if to be admitting to it - the secret is out
and
How would you know? - probably a remark, the person thinks that the other person will not know
A. I know what you were talking about. B. How would you know?
This could be true or false, the person is not replying directly, but is just stating how the person would have found out.
In response to your second question, again, you should look here.
Best Answer
Wouldn't is a contraction of "would not" and denotes a lack of permission or willingness on the part of the subject. Your father didn't want to let you borrow the car, and the landlady didn't want you to have guests.