It should be the <<the hallway carpet is dirty>>. The way you have it the Romanian way of order of words.
We are not here to learn english. Especially not incorrect english. It is not "from"
Possibly that it is a Romanian course to me it is more important that the Romanian is correct. Unless a Romanian is doing the course to learn English then it is a problem. I am from South Africa and I'm learning some American English in this course.