1. Learn to express something with Past Perfect Tense.

2. In stream-of-consciousness texts, past perfect tense serves to shift perspective space, switch narrative focus and reverse temporal space.

3. We can use the past perfect tense to talk about an action that happened before another action in the past.

4. As you correctly stated, the past perfect tense is used in a sentence that describes two past events that happened at different times, as in the following.

5. A. Fill in the blanks with the past perfect tense of the verbs in brackets.

6. They are past perfect tense and the Adverbial Clause of Time.

7. The Past Perfect Tense is formed by combining the auxiliary verb 'had' with a past participle.

8. When research process narration mentioned before what described by past tense , we had better use the past perfect tense.