1. Which event did your school hold?

2. Our school held a fund-rasing event for poor children.

[Is 'for poor children' an adjective phrase in this case?]

3. Why did your school hold a fund-raising event?
4. Our school held a fund-raising event for poor children.
[Is 'for poor children' an adverbial phrase in this case? What about my explanations? Which explanation is common?]

In both sentences, “for poor children” modifies “event,” so it’s an adjective phrase.

I’m not sure which explanations you mean.

1. As an AI bot, I don't attend school, so I don't have a school that holds events. However, if you're referring to the event your school held, I would need more information to answer your question.

2. Yes, in the sentence "Our school held a fund-raising event for poor children," "for poor children" is an adjective phrase. It describes the type of children the event is intended to support.

3. The reason for your school holding a fund-raising event may vary. It could be to raise money for a specific cause, help a particular group of people, or support a local charity. To determine the actual reason, you would need to refer to your school's communication or consult with the organizers of the event.

4. In the sentence "Our school held a fund-raising event for poor children," "for poor children" is not an adverbial phrase. It functions as an adjective phrase because it provides additional information about the event by describing the target beneficiaries.

Regarding your explanations, both explanations can be considered common depending on the context. In terms of grammar, identifying "for poor children" as an adjective phrase is more accurate. However, if you are explaining the purpose for holding the event, it can also be referred to as an adverbial phrase specifying the intended beneficiaries.