Hello, Rex
Those "wh-words" mentioned serve more than one purpose in English. It is true that they are not used only in questions.
There are two big groups of questions:
a. "yes-no questions": these begin with a verb, usually an auxiliary, and require "yes" or "no" for an answer. the questions are formed by inversion of verb and subject, or by adding an auxiliary verb at the beginning.
"Are you ok?"
"Did you see Tom yesterday?"
b. "wh-questions": this group inclused all the so-called "question words" mentioned in the previous posts and require new information as an answer. These questions start with the "question word" that replaces the unknown information.
"How old are you?"
"What time does the next train leave?"
In writing, what tells you that a certain construction is a question is the "word order" in that structure.
1. "You could turn on the T.V" is a statement.
2. "Could you turn on the T.V.?" is a question.
This will still be so even if you forget to place the question mark at the end in #2.
The above are basic rules, and you can have a question within a longer structure. The question may not be at the beginning of that structure. That is the case with the structure in the text you posted: it is a question, even when it may not look like one at first sight.
Suppose the construction had been:
"Could we learn something from our neighbours, the French, since Britain and other countries in Europe worry about ever-growing levels of obesity among adults and children?"
In this case, it would have been easier -perhaps- to recognise the question. "Since Britain... and children" is not the main part of the sentence, but a comment; the reason why the British could learn from the French.
I hope it helps.
Miriam