Is there a reason that Raj (as the subject) can't come at the beginning of the sentence? I did subject-postpositional phrase-verb, but Duolingo rejected it

Is कमरे in an oblique case because of the post position f में? I used "kamra" and it was wrong.

Why is this not accepted? "राज इस कमरा में खाता है"

I figured it out. I had कमरा and not कमरे

इस कमरे में राज खाता है

or

राज इस कमरे में खाता है

are both acceptable.

Same doubt