The correct preposition here is "for." The phrase "he went for a walk in the park" indicates the purpose of his going out. Using "in" would imply being inside the park, while "at" would suggest a location, and "to" implies direction rather than purpose. Understanding how to express intentions and purposes accurately is essential for clear communication in English. Misusing prepositions can lead to confusion; for instance, saying "he went in a walk" suggests a misunderstanding of the action. Clear expression of activities and intentions helps avoid miscommunication, particularly when discussing plans or outings.
Preposition