53587
I learned that the particle に is meant to mark the place in a phrase, similar
to _in, on and at_. But today I was reading Yotsubato and I came across this
phrase **元気にしてたか** and obviously this rule doesn't apply to 元気.

It didn't stop me to understand the conversation (at least I think so), I
presume it meant something like:

> How you doing? Good?

Am I wrong in this? Why use the particle に in this phrase?
CC BY-SA 3.0
2017-10-01T13:20:12.923
53583
2017-10-01T21:52:14.780
25472
question
grammar translation
Why use に in 元気にしてたか？
元気 is a na adjective

To describe the verb していた（する), we add に to make 元気an adverb.
CC BY-SA 3.0
2017-10-01T21:52:14.780
53587
2017-10-01T21:52:14.780
25999
53583
answer