We can all speak and understand each other; do we need to investigate how?

3.3 General questions
In general questions the speaker is interested to know whether some event or phenomenon asked about exists or does not exist; accordingly the answer may be positive or negative, thus containing or implying “yes” or “no”.
A general question opens with a verb operator, that is, an auxiliary, modal, or link verb followed by the subject. Such questions are characterized by the rising tone.

Does your sister go figure-skating?

Is that girl a friend of yours?
Can you speak French?

“Yes-no” questions may be incomplete and reduced to two words only: Can you? Does he?

A negative "yes-no" question usually adds some emotional colouring of surprise or disappointment.

Haven’t you posted the letter yet? (Why?)

General questions opening with will/would may be considered as commands and requests according to their communicative role (see § 17).

Owing to their occasional emotional colouring, “yes-no” questions may function as exclamations
3.4 Alternative questions
An alternative question implies a choice between two or more alternative answers. Like a “yes-no” question, it opens with an operator, but the suggestion of choice expressed by the disjunctive conjunction or makes the “yes-no” answer impossible. The conjunction or links either two homogeneous parts of the sentence or two coordinate clauses. The part of the question before the conjunction is characterized by a rising tone, the part after the conjunction has a falling tone.

Will you go to the opera or to the concert to-night?

3.5 Suggestive questions
Suggestive questions, also called declarative questions, form a peculiar kind of "yes-no" questions. They keep the word order of statements but serve as questions owing to the rising tone in speaking and a question mark in writing, as in:


You really want to go now, to-night?
- Yes, nothing could make me stay.

By their communicative function suggestive questions resemble sentences with tag questions; they are asked for the sake of confirmation. The speaker is all but sure what the answer will be (positive or negative), and by asking the question expects confirmation on the part of the ad­dressee.