QUESTION: Does the verb BE always link a subject to a complement?
ANSWER: If there’s one grammar topic that will take me the rest of my life to understand completely, it may be complements! Recent questions on my forum have tested my humble knowledge on this topic. If only I could start with clear questions. I do not mean to imply that the learners lacked the ability to word questions clearly. Instead, the source of confusion itself is murky, so I must first explore the nature of each question before I can start searching for answers.
One question concerned the use of a prepositional phrase after BE: The professor is of German descent. The learner wanted to know why the preposition could be in that position. I replied that some may identify “of German descent” as a subject complement, but I knew that more of an explanation was needed. Greenbaum and Quirk helped me confirm that complements are typically noun or adjective phrases, while adverbials are generally adverb phrases, prepositional phrases, or a clause (207). However, they also recognize the odd behavior of prepositional phrases when they are semantically similar to adjective or noun phrases: “The distinction between obligatory adverbial and complement is not clear-cut for all prepositional phrases” (208).
In short, if we focus on semantics, “of German descent” describes the subject. We could just as easily use an adjective and say, “He is German.” Greenbaum and Quirk noted other prepositional phrases with noun or adjective equivalents: under suspicion – suspects / in good health – healthy (208). We could add idiomatic expressions, such as out of this world – awesome / off his rocker – crazy. From the standpoint of semantics, all these prepositional phrases can behave like a complement, defining the subject. In contrast, the prepositional phrase “in my office” merely completes the sentence as an adverbial: I am in my office. BE is used to express existence, and the prepositional phrase gives information about my location. Agreed?
A second question had me looking hard at a very common structure, so common that I never really thought about labeling all the parts. Another learner wanted to know about the use of existential there, i.e., using there as a dummy subject. The question concerned the phrase “There should be…” and focused on the role of BE. I’ve always just worked with ”there is/ there are” as a single unit used to state the existence of something: There are many problems in the world. There will be many joys ahead. There should be rainbows in every childhood. ”There” isn’t the true subject of the sentence. We know whatever follows BE is the subject: problems, joys, and rainbows. It doesn’t matter what form BE takes.
In this use, Biber et al. refer to there as an anticipatory subject (88). If the true subject follows BE, then we cannot label that subject as a complement as well. Instead, we could place “there” in parentheses and label our true subjects as problems, joys, and rainbows, noting that BE remains a copular verb expressing existence, but it isn’t there to link the subject to a complement: Many problems are in the world. Many joys will be ahead. Rainbows should be in every childhood. In these new sentences, aren’t we simply using a prepositional phrase or an adverb to indicate time and place (i.e., adverbials)?
Now the short answer: Does the verb BE always link a subject to a complement. - No.
Biber D. et al. (2007). Longman grammar of spoken and written English. Essex: Pearson Education Limited.
Greenbaum S. and Quirk R. (1995). A student’s grammar of the English language. Essex: Longman Group UK Limited.