Answer:
1. Had had.
2. Hadn't tidied.
3. Had done.
4. Had tidied.
5. Hadn't done.
6. Hadn't seen.
Explanation:
A verb is one of the parts of speech in English language. Verbs can be defined as any word that describes an action, occurrence, or state of existence. Some examples of verb are dance, sing, walk, play, run, sit, etc.
In English language, to form a past perfect tense, you should use the past tense of "have" which is had in addition with the past participle of the main verb such as tidy, see, do, clean, etc.
This ultimately implies that, a past perfect tense comprises of two main parts; the past tense of have (had) and the past participle of the main verb.
Some examples of past perfect tense include the following;
1. Amy didn't invite Jack to the party because they had had (have) a fight earlier in the week. The past participle of "have" is had.
2. Daisy's dad was angry with her because she hadn't tidied (not tidy) her bedroom. The past perfect form of "not tidy" is hadn't tidied.
3. I didn't have to take the dog for a walk because Joey had (have) already done (do) it. The past participle of "have" and "do" are had and done respectively.
4. The house was looking really clean because mum and dad had tidied (tidy) everything away. The past participle of "tidy" is had tidied.
5. Kim had to miss her homework because she hadn't done (not do) her homework. The past perfect form of "not do" is hadn't done.
6. The driver almost caused an accident because he hadn't seen (not see) the red light. The past perfect form of "not see" is hadn't seen.
