verb "to be"
The verb to be is unique in the English language. It can serve as a main verb (I am a writer) and as a primary auxiliary verb to form the progressive tense (I am writing the book) and the passive voice (The book was written by me).
Ordinarily, it requires only four words to perform a complete conjugation of a regular verb (decide, decides, decided, deciding). It can require five words for a complete conjugation of an irregular verb (drink, drinks, drank, drunk, drinking).
But it requires eight words to conjugate the verb to be (am, is, are, was, were, been, being, be).
As a main verb, the verb to be will be followed by (1) a noun, the predicate nominative, (2) an adjective, the predicate adjective, or (3) a phrase showing where or when something is.
Many writers use far too many constructions of the verb to be in their style. Powerful writers, on the other hand, write with action verbs. Please, you must read chapter 2 of the eBook Developing a Powerful Writing Style. In that chapter, you'll find that I did not use a single construction of the verb to be in the 2,200 words in the chapter.