The simplest way is to ask them directly. You just have to go up to that person and ask that person about their surname. But in case that you are not so well acquainted with that person or have some other reason as to why you cannot approach that person directly then you would have to rely on more devious techniques. You can find out a common acquaintance who knows both you and the person who surname you are trying to find out and get the required information from this common acquaintance.
Otherwise, if you are familiar with the places that this person likes to frequent then you can also try to extract information from these places by using a little cunning. If you know where this person lives then you can even get his surname form the directories. Thus if you want there are several ways of finding the surnames of people.
Otherwise, if you are familiar with the places that this person likes to frequent then you can also try to extract information from these places by using a little cunning. If you know where this person lives then you can even get his surname form the directories. Thus if you want there are several ways of finding the surnames of people.