I've been given two examples:

> Niwa ni ki ga arimasu

and

> Kono heya ni wa nani ga arimasu ka?

Why is `wa` required in the second sentence, but not in the first one?

Thank you in advance!
CC BY-SA 4.0
2019-01-25T17:12:35.223
65077
2019-01-25T17:12:35.223
32507
question
particles
Particles after に