1. With "have" for perfect tenses:
* Present Perfect: I have eaten breakfast.
* Past Perfect: They had finished their work.
* Future Perfect: We will have completed the project by tomorrow.
2. As adjectives:
* The broken vase lay on the floor.
* He had a tired look on his face.
* The stolen painting was recovered.
3. With "get" and "become" for passive voice:
* The book got published last year. (instead of "was published")
* He became known for his talent. (instead of "was known")
4. In phrasal verbs:
* I picked up the phone. (picked = past participle)
* They gave up trying. (given = past participle)
5. With "to be" for passive voice in certain contexts:
* To be seen is to be believed. (This is a common idiom where "to be" is used with a past participle to form a passive voice).
Examples:
* The letter written by John was very heartfelt. (written = past participle used as adjective)
* The game played yesterday was exciting. (played = past participle used as adjective)
* They had been informed of the changes. (had been informed = past participle used in past perfect tense)
Remember: Past participles are used in various grammatical structures, and their use is influenced by the context and tense of the sentence.