Locational Markers へ, に, で
へ and に as destination markers
The two particles へ and に are interchangeable particles used when referring to something moving from one location to another. In these cases, the へ is pronounced as え. When used subsequent to interrogatives such as どこ(doko) and どこか (dokoka), these particles are not dropped.
Uchi (e/ni) kaerimasu .
I am going home.
Ashita, doko ka (e/ni) iku tsumori desuka?
Do you plan to go anywhere tomorrow?