An essential relative clause provides necessary, defining information about the noun. On the other hand, non‐ essential relative clauses provide additional, non‐necessary information about the noun.

The preceding chapter showed how sentences can be streamlined by reducing their adjective clauses to adjective phrases — a simple process that omits the relative pronouns “that,” “which,” “who,” “whom ...

The mark of fluent English-language writers or speakers is the way they effortlessly do away with words mandated by formal grammar — which only impede the quick delivery of their ideas. Nonnative ...