Grammar

Grammar is the study of the structure of words, phrases, clauses and sentences which make up language.

You don't need to know the grammar of a language in order to speak it, and often no grammar is taught with in formal language  learning. Grammar is not fashionable. Why ?

If you understand the grammar of a language, you can not only make new sentences, but you can understand why you make them as you do.

Before you can analyse the grammar of a language, you have to learn the terminology and know with confidence the meaning of  a phrase, clause, sentence, adjective, participle, apposition(?) and more.

This is one powerful reason for studying Latin to at least some degree.