The phrase “based on what” is often used to ask someone about the grounds or reasons for their assertion, decision, or action. It’s akin to asking, “On what grounds?” or “What is your reasoning?”
Here are two examples in sentences:
Example 1:
When his friend claimed that their favorite team would win the championship, Jake asked, “Based on what? They’ve lost their last five games.”
Example 2:
During the meeting, when the manager suggested a new marketing strategy, Susan questioned, “Based on what evidence or data are we changing our approach?”
Here are two examples in conversation:
Example 3:
Ben: I think we should change our investment strategy.
Emma: Based on what? Our current strategy is yielding good returns.
Example 4:
Lucy: I’ve decided to change my major to anthropology.
Mark: That’s a big decision. Based on what did you make that choice?
So, when someone asks “based on what“, they’re asking for the reasoning, evidence, or justification behind a claim, decision, or action. It’s a way of seeking more information or challenging the validity of an argument.
