The correct preposition here is "on." The phrase "she was born on January 15th" indicates a specific date. Using "in" would be appropriate for months or years, while "at" generally refers to specific times or locations, and "for" indicates purpose. Understanding the correct use of prepositions when discussing dates is essential for clear communication in English. Misusing prepositions can lead to misunderstandings about important events; for instance, saying "she was born in January 15th" is incorrect. Clarity in expressing dates is crucial, particularly in formal writing and conversation, where precise information about timelines is necessary for accurate communication.
Preposition