¿Por qué?
Duration of time (por)
By a certain time (para)
By means of (por)
Per (por)
intended for. (para)
Duration of time
By a certain time
By means of
Per
Thank you for always uses por.
An exchange uses por
Going to a destination uses para
Passing through or around uses por
Comparisons use para
To pick something up uses por
Movement through or around uses por