Decorative illustration of orange roses at the bottom right corner of a grammar worksheet.

To solve the problem of identifying the main clause and the subordinate clause in each sentence, we need to understand the definitions of these clauses:

- Main Clause: A main clause is a complete sentence that can stand alone. It contains a subject and a predicate and expresses a complete thought.
- Subordinate Clause: A subordinate clause is a dependent clause that cannot stand alone as a complete sentence. It usually begins with a subordinating conjunction (e.g., "because," "when," "which," "that," etc.) or a relative pronoun (e.g., "who," "which," "that").

Let's analyze each sentence and identify the main and subordinate clauses:

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1. The moon, shining like a light, was directly overhead.

- Main Clause: *The moon was directly overhead.*
- Subordinate Clause: *shining like a light* (participial phrase acting as a subordinate clause)

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2. The stolen car sped up the hill, chased by two police cars.

- Main Clause: *The stolen car sped up the hill.*
- Subordinate Clause: *chased by two police cars* (past participle phrase acting as a subordinate clause)

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3. The flowers, which had bloomed in the spring, were fading fast.

- Main Clause: *The flowers were fading fast.*
- Subordinate Clause: *which had bloomed in the spring* (relative clause)

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4. Steven, a year younger than me, was not allowed to go.

- Main Clause: *Steven was not allowed to go.*
- Subordinate Clause: *a year younger than me* (participial phrase acting as a subordinate clause)

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5. The room was filled by a strange noise that echoed through my head.

- Main Clause: *The room was filled by a strange noise.*
- Subordinate Clause: *that echoed through my head* (relative clause)

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6. Mum sat on the sofa, while the children played on the floor.

- Main Clause: *Mum sat on the sofa.*
- Subordinate Clause: *while the children played on the floor* (adverbial clause)

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7. The new pupil smiled shyly as she was introduced to the class.

- Main Clause: *The new pupil smiled shyly.*
- Subordinate Clause: *as she was introduced to the class* (adverbial clause)

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8. The sun, which was now directly overhead, was incredibly hot.

- Main Clause: *The sun was incredibly hot.*
- Subordinate Clause: *which was now directly overhead* (relative clause)

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9. The present, wrapped in silver paper, was under the Christmas tree.

- Main Clause: *The present was under the Christmas tree.*
- Subordinate Clause: *wrapped in silver paper* (participial phrase acting as a subordinate clause)

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10. We looked up in surprise when we heard Aisha’s scream.

- Main Clause: *We looked up in surprise.*
- Subordinate Clause: *when we heard Aisha’s scream* (adverbial clause)

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11. I knew I was nearly home because the car was slowing down.

- Main Clause: *I knew I was nearly home.*
- Subordinate Clause: *because the car was slowing down* (adverbial clause)

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12. Miss Gerrard, who teaches English, hates the misuse of the possessive apostrophe.

- Main Clause: *Miss Gerrard hates the misuse of the possessive apostrophe.*
- Subordinate Clause: *who teaches English* (relative clause)

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Final Answer:

\boxed{
\begin{aligned}
&1. \text{Main: The moon was directly overhead. Sub: shining like a light} \\
&2. \text{Main: The stolen car sped up the hill. Sub: chased by two police cars} \\
&3. \text{Main: The flowers were fading fast. Sub: which had bloomed in the spring} \\
&4. \text{Main: Steven was not allowed to go. Sub: a year younger than me} \\
&5. \text{Main: The room was filled by a strange noise. Sub: that echoed through my head} \\
&6. \text{Main: Mum sat on the sofa. Sub: while the children played on the floor} \\
&7. \text{Main: The new pupil smiled shyly. Sub: as she was introduced to the class} \\
&8. \text{Main: The sun was incredibly hot. Sub: which was now directly overhead} \\
&9. \text{Main: The present was under the Christmas tree. Sub: wrapped in silver paper} \\
&10. \text{Main: We looked up in surprise. Sub: when we heard Aisha’s scream} \\
&11. \text{Main: I knew I was nearly home. Sub: because the car was slowing down} \\
&12. \text{Main: Miss Gerrard hates the misuse of the possessive apostrophe. Sub: who teaches English} \\
\end{aligned}
}