途中に・途中で

途中に and 途中で both mean “in the middle of” something, but they are used in slightly different ways. 途中に is used to indicate that something happens at a point inside the span of an ongoing action or journey, often when something unexpected occurs or when you notice something along the way. It tends to describe a point along the path or period where another event occurs. 途中で is used for events that interrupt or occur during the course of an action, often implying a break, interruption, or notable moment within that ongoing activity. Both can be attached to a whole verb phrase (by using the dictionary form or ている form) or to a noun phrase with の, but the nuance shifts slightly as described above. Typical contexts include travel, ongoing activities, or processes where another event happens partway through.