"The soap is in the bathroom."
Translation:Το σαπούνι είναι στο μπάνιο.
You are right, it could also be like this. But in daily speech we don't say it so often (μέσα στο μπάνιο, μέσα στο δωμάτιο,...), cause "μέσα" is usually said for describing smaller spaces (e.g. μέσα στο ντουλάπι = inside the closet, and even here it's not necessary to use "μέσα")
When στην is followed by a word that begins with κ,π,τ,ψ,ξ,γκ,μπ,ντ or a vowel it keeps the -ν. Otherwise it is ommited.This rule also applies to την, αυτήν and the negatives δεν, μην, but not to στον/τον/αυτόν. (though you will come upon some sentences in the cource that ommit the -ν from στον/τον/αυτόν, it is wrong.)
"Το σαπούνι είναι στην τουαλέτα." is correct and one of the accepted translations. We don't know why your sentence wasn't accepted.
You should make a Report when your senten ce is not accepted so we can see what the problem was.
TIPS TO HELP YOU LEARN + HOW TO REPORT A PROBLEM
And check out the Greek Forum here with more links.
We still can't find it.
First, are you working on the web or phone.
If you are on the web do this>
Here's how to REPORT.
Go to the bottom of the exercise page where you'll see "REPORT" Click on that:
Then choose what you want to REPORT: (You'll see these to choose from.)
-The audio does not sound correct.
-The dictionary hints on hover are wrong or missing.
-The Greek sentence is unnatural or has an error.
-The "Correct solution" is unnatural or has an error.
-My answer should be accepted. This is the one you should click on if your translation was not accepted.
After choosing the REPORT you want to make you should post on the comment page.