Learn English – “Would you like me to show?”, or “would you like to have me show?”

Great Question! I was intrigued to find the following in NOAD:

As with shall and will, there is confusion about when to use should and would. The traditional rule is that should is used with first person pronouns ( I and we), as in: I said I should be late, and would is used with second and third persons ( you, he, she, it, they), as in: you didn't say you would be late.

In practice, however, would is normally used instead of should in reported speech and conditional clauses: I said I would be late; if we had known, we would have invited her.

In spoken and informal contexts, the issue rarely arises, since the distinction is obscured by the use of the contracted forms I'd, we'd, etc. In modern English, uses of should are dominated by the senses relating to obligation (for which would cannot be substituted), as in: you should go out more often, and for related emphatic uses, as in: you should have seen her face!

1. I’m sure all of these variations are commonly used and understood to mean roughly the same thing. “I would have thought…” essentially means “I believe you should have understood what I meant,” or “that should be obvious.” “I thought that was obvious” is a simple declaration that sounds more like the speaker actually gave the matter some thought.

2. “I should [not “would”] have known,” means that she realizes, after finding the boys, that she should have expected to find them where she did. “I knew you would be here” is similar, but means that she went straight to wherever she found the boys based on her knowledge of their habits. Both phrases might imply some disapproval of their being there. “I would know” (or “I should know”) is not a possible substitute for your sentence. As a complete clause, it’s more like “you can take my word for it,” or “take it from me,” implying some experience of a situation, often said ruefully or with a little chagrin.

3. “I don’t/wouldn’t know”: There wouldn’t be much reason to answer “I don’t know”; it’s more direct to just say that you weren’t there. “I wouldn’t know” might be employed where there’s some displeasure, like if B thought he should have been invited to the party but wasn’t. The “would” in “I wouldn’t know” is present tense; “I wouldn’t have known” is not possible here because it puts it in the past tense.