"The dorm looked like a prison. (For) how long would he have to live here?"
As far as I know, both are grammatical. But which is more common?
"The dorm looked like a prison. (For) how long would he have to live here?"
As far as I know, both are grammatical. But which is more common?
"How long would he have to live here?" is certainly more common than "For how long would he have have to live here?"
However, "For how many years would he be living here?" is also good, and conveys that the time feels long enough that measuring in years would be appropriate.