Here are the completed sentences:
- We have never seen that film.
- You have never found a dinosaur.
- My parents have never spoken English.
Explanation:
* Sentence 1: The subject "We" requires "have". The past participle of "see" is "seen".
* Sentence 2: The subject "You" requires "have". The past participle of "find" is "found".
* Sentence 3: The subject "My parents" is plural and requires "have". The past participle of "speak" is "spoken".