"Which students in the class are allowed to go to the party will be decided by the teacher."
I am not sure whether the sentence "Which students in the class are allowed to go to the party" can be the subject of the entire sentence.
Could you please explain why this expression may be wrong?
The painter selects which color to use.
Which color to use is selected by the painter.
The chef decides how to cook the food.
How to cook the food is decided by the chef.
The traffic cop decides when to let traffic through.
When to let traffic through is decided by the traffic cop.
The doctor explained why it is important to take the medicine.
Why it is important to take the medicine was explained by the doctor.
The coach determines who will play.
Who will play is determined by the coach.
The speech writer decided what to say.
What to say was decided by the speech writer.
The foreman decided where the men would work.
Where the men would work was decided by the foreman.
The portfolio manager decides whether to buy or to sell.
Whether to buy or to sell is decided by the portfolio manager.
The tour guide decides which site to visit.
Which site to visit is decided by the tour guide.
"Which students in the class are allowed to go to the party" is a clause, not a sentence. Clauses can technically be the subject collectively, but what I would call the real subject is "students," because the rest of the clause is not essential to the while sentence making sense.
