The Sentence Diagram Generator will visually represent the grammatical structure of the sentence: "It was a bright cold day in April, and the clocks were striking thirteen."

1. Main Clause 1: "It was a bright cold day in April"

   • Subject: "It"
   • Verb: "was"
   • Predicate Noun: "day"
     • Adjectives: "bright," "cold"
   • Prepositional Phrase: "in April"
     • Preposition: "in"
     • Object of the Preposition: "April"

2. Coordinating Conjunction: "and"

3. Main Clause 2: "the clocks were striking thirteen"

   • Subject: "the clocks"
   • Verb: "were striking"
   • Direct Object: "thirteen"

This structure can be visually diagrammed to illustrate the relationships between the components of the sentence.