Identifying Past Perfect Tense

The past perfect tense indicates an action completed before another past action or time. It requires the auxiliary verb $had$ followed by the past participle of the main verb.

The standard structure is:

• Subject + $had$ + Past Participle

Analyzing Grammar Options

We will check each option to find the sentence matching the past perfect structure:

• Sentence A: $I read a lot about mythology.$ - This is Simple Past Tense.
• Sentence B: $I had been reading a lot about mythology.$ - This is Past Perfect Continuous Tense (uses $had$ + $been$ + Verb-ing).
• Sentence C: $I was reading a lot about mythology.$ - This is Past Continuous Tense (uses $was$ + Verb-ing).
• Sentence D: $I had read a lot about mythology.$ - This matches the Past Perfect Tense structure ($had$ + Past Participle $read$). The past participle of 'read' is spelled the same as the simple past.

Conclusion on Past Perfect Tense

Sentence D correctly uses the past perfect tense by employing the auxiliary verb $had$ followed by the past participle $read$.

Therefore, the option representing sentence D is the correct choice.