Say where something or someone is
に marks the place where someone or something simply exists.
JLPTN5
place + に + いる / ある~ ni iru / aru
[something] is / exists at [place]
Example Sentence

I'm at home
Use に with existence verbs like いる and ある to say where something is located. This contrasts with で, which marks where an action takes place: に is for static being, で is for dynamic doing.
Tips and Common Traps
Build the Sentence
JLPT N5There is a dog in the park
Arrange the words in the correct Japanese order:
いる
there is が
subjectいぬ犬
dog に
location / timeこうえん公園
park