This document contains the notes from an English lesson on restrictive and non-restrictive clauses. It defines restrictive clauses as essential information that cannot be omitted from a sentence. It defines non-restrictive clauses as additional information set off by commas that can be omitted. Examples are provided to illustrate the difference. Students then participate in exercises to identify restrictive clauses in sentences and answer riddles by forming sentences with restrictive and non-restrictive clauses.