As should be clear in the title of this textbook, the key consideration is to always analyze in context. This means that you need to look closely at “who the word (or phrase or clause) is hanging out with” in the CONTEXT of the sentence. You can NOT depend on lists alone.

As we discuss in the Form and Function page, you can analyze forms at the clause level, at the phrase level, and at the word level. You can also analyze the functions of each of these forms at the clause level, at the phrase level, and at the word level. AND, you can analyze for form and function within each of these levels. Throughout the textbook we will offer examples of analyses at each level. For example, let's look at the following "simple" sentence from The Stranger:

For a moment I had an absurd impression that they had come to sit in judgment on me.

You can analyze the form and function of the dependent clause (THAT THEY HAD COME TO SIT IN JUDGMENT ON ME - adjectival relative clause), and within that dependent clause you can also analyze the form and function of phrases operating within that clause (TO SIT - nominal infinitive phrase; IN JUDGMENT - adverbial prepositional phrase; ON ME - adjectival prepositional phrase); moreover, you can also analyze the form and function of individual words within those phrases (or within those clauses). The important thing to remember is that you always analyze in the context of that particular structure by focusing on who is hanging out with whom and how elements are working together.

Another reason for always analyzing in context is that most words have the ability to function in many different ways. For example, you can’t just assume that a word is a preposition because it is on a list in Section 4 of Analyzing Grammar in Context. That word might also show up on another list as a subordinator. And the only way that you can name it correctly is to determine “who it’s hanging out with.” If the word precedes a noun or nominal phrase ONLY, then it’s a preposition; instead, if it precedes a complete clause (with NP subject and MVP) it’s a subordinator. This means that you can't make assumptions or generalizations acontextually or identify the form or function of a word, phrase, or clause without considering the words that precede it or follow it. 

We will put this abstract concept into practice throughout Analyzing Grammar in Context.