"Upon leaving the station I saw a man."
Translation:Al salir de la estación vi a un hombre.
Glad it was multiple choice because I would not have gotten "al salir de" to be 'Upon leaving". I guess its just one you got to remember.
"Al + infinitive" is a set construction that means "upon (gerund of infinitive)"
Al salir = upon leaving
Al llegar = upon arriving
Al llamar = upon calling
edit- So if I said "Al leer el libro yo puedo ahora hacer una computadora" Upon reading...
what is the difference between salir and dajar that makes dajar incorrect in here?
Dejar is indeed 'to leave' but when I searched out using 'al dejar' I found 'upon leaving' described as ' Después de dejar' which to me means 'after leaving'. So it may be the more common expression.
You hit a good point, this was my question too about the persona ''a'' Why it is needed in this sintince? Can anyone explation i'll be really grateful. Thanks in advance.