I have some questions..

[Anonymous]

Dear teacher
Would you tell me answers to my questions?

Q1. What does the word "by" in the sentence below mean?
Since 1978, the amount of money available to buy books has fallen by 17 %.

Q2. Why isn't there "?" at the end of the following sentence?
When you cook, could you please tidy up after yourself.

Thanks a lot.
Aba

[RonBee]

Q2. Why isn't there "?" at the end of the following sentence?
When you cook, could you please tidy up after yourself.

Since that sentence is worded as a question, there should be a QM there.

(QM = question mark)

[Tdol]

Some people leave the question mark off when the question is a request.

[RonBee]

Some people leave the question mark off when the question is a request.

That is true, but should they?

:)

[Tdol]

Grammatically no, but there are times when it seems to make more sense without a question mark.

[RonBee]

But isn't that the whole point of a question mark--to indicate a request?

Example: "Take out the trash, would you?"

[Tdol]

Some BE speakers don't see that as a question- the logic behind it is an assumption that the person will agree.

[RonBee]

It may be assumed by the speaker that the "answer" is "yes", but don't you still need the QM to indicate inflection?

[Tdol]

I think it's generally regarded as optional- people would include it or not according to what they saw as the sense of the request.