What kinds of sentences/ clauses are used for basic grammar study?

What came first? The grammar book or the language? The dictionary or the words. In natural language development books that define words and that exemplify grammar rules ALWAYS come afterwards. But what kind of language use is deemed ok or not?

When writing a grammar book, a certain kind of language is used. In it's basic form, grammar is studied using written (not spoken) language, using formal (not informal) language, using declarative clauses (not interrogatives), using positive (not negative), using active (not passive) forms, & using constructed (not artistic) language, using simple rather (not multiple) sentences/ clauses.   Video time ! Hope it helps.