Formal:
* Interrogate: This suggests a more formal and intense questioning, often used in legal or investigative contexts.
* Scrutinize: This implies a careful and detailed examination of something.
* Probe: This suggests a more exploratory and in-depth questioning.
* Cross-examine: This refers to questioning someone in a legal setting, particularly by an opposing lawyer.
Informal:
* Grill: This is a more informal term, suggesting a vigorous and intense questioning.
* Pick apart: This implies a critical and detailed examination of something.
* Pursue: This suggests following up on a question or line of inquiry.
* Inquire: This is a more neutral term, simply meaning to ask questions.
* Challenge: This implies questioning something with the intention of proving it wrong.
* Press: This suggests pushing for answers or information.
The best word to use will depend on the context of your sentence.