Why is it that you sometimes put "por" and sometimes not. Such as in "Yo pago tu estudias".
The verb "pagar" means to "to pay for". The "for" is built into it. The "por" seems redundant, but most the examples I remember use "por". "pago por tu" has 5,210,000 google results and "pago tu" has 155,000 results. Maybe duolingo's example is a bit odd.
Tú pagas POR el hotel ... you pay FOR the hotel. Yo pago, tú estudias... I pay, you study. (no FOR needed)
I agree. To say "you pay ..." is more like a command, which is not what is written. The tenor of it seems to be a reminder ... just to remind you, you are paying for the hotel.