In which sentence is the underlined word a past participle?

Melted rock can explode or flow from different types of volcanoes.
Having been warned of a possible eruption, the people left their town at the base of the volcano.
Flowing lava from a volcano is an amazing sight to see.

Melted rock can explode or flow from different types of volcanoes.

And the underlined word(s) is/are ... ????

Note that past participles have normal past tense endings on them (-d, -ed, -t, or maybe something irregular, such as "gone").

Present participles have only one ending: -ing.

What do you think?

The underlined word "warned" in the sentence "Having been warned of a possible eruption, the people left their town at the base of the volcano" is a past participle.

To find the sentence in which the underlined word is a past participle, let's first understand what a past participle is. A past participle is a verb form that typically ends in "-ed" (regular verbs) or has an irregular form (like "spoken" or "gone"). It is used to form various verb tenses and is often used in passive voice constructions.

Now, let's analyze the sentences provided:

1. "Melted rock can explode or flow from different types of volcanoes."
In this sentence, the underlined word is "melted." This is a past participle as it has the "-ed" ending, which indicates that the action of melting has already occurred.

2. "Having been warned of a possible eruption, the people left their town at the base of the volcano."
In this sentence, the underlined word is "been." Although "been" is a verb, it is part of the verb phrase "having been warned," where "having" functions as the present participle and "been" functions as the past participle. So, "been" is a past participle.

3. "Flowing lava from a volcano is an amazing sight to see."
In this sentence, the underlined word is "flowing." While "flowing" is a verb form, it is used as a present participle here, not a past participle. Present participles typically end in "-ing."

Therefore, the sentence in which the underlined word is a past participle is: "Having been warned of a possible eruption, the people left their town at the base of the volcano."