When asking a general question about something in English, should they be formed in plural or in singular? Or rather what is a good way of forming it?
How are articles used in English?
How is an article used in English?
Both are grammatical ways of making a generic reference. (It is, incidentally, a strange question. Proverbs do not usually have any particular construction.)
EDIT: The same applies to your edited post. A third way in that particular case is to use the definite article: How is the article used in English? although some might object to that on the grounds that English has more than one article.