Here's a breakdown:
* Under: This word implies a situation or context.
* What: This refers to the specific conditions or circumstances.
* Circumstances: These are the surrounding facts or events that influence a situation.
Here are some examples:
* "Under what circumstances would you resign from your job?" (This asks about the specific situations that would lead to the person quitting.)
* "Under what circumstances can I use this software for free?" (This asks about the specific conditions under which free use is allowed.)
* "Under what circumstances is it illegal to park here?" (This asks about the specific conditions that make parking illegal.)
In general, "under what circumstances" seeks to understand the specific conditions or situations that determine the occurrence or truth of something.