Hello there. To answer your question, I'll try to make it simple. Both words (i.e. Nasaan and Saan) basically mean the same thing and that is to ask "where". However, in real life Filipino conversation, they are used in different context. I'm going to explain it to you as to how we use it in real conversation. The question word "saan" is basically used for asking places or location of an action. For example: • Saan tayo kakain? (Where shall we eat?) • Saan pumunta si Brian? (Where did Brian go?) • Saan gaganapin ang 2012 Olympics? (Where will the 2012 Olympics be held?) You can simply answer these "saan" questions by using the word "sa" added with the place that is being asked. • Sa canteen (tayo kakain) • Sa paaralan (pumunta si Brian) • Sa London (gaganapin ang 2012 Olympics) Although in conversational Filipino, you don't have to complete the sentence. The question "saan" can also be answered by demonstrative pronouns in Filipino like: dito, diyan, doon. On another note, the question word "Nasaan" is generally used for asking location of a person or thing. I should emphasize that this question word is for asking where a person is or the location of the person or thing. Nasaan is usually followed by a noun or pronoun and is being introduced by articles "si" and "ang" (i.e. si and ang for singular) or "sina" and "ang mga" (i.e. sina and ang mga for plural). • Nasaan ang aking libro? (Where is my book?) • Nasaan si Amy? (Where is Amy?) • Nasaan ang lapis ko? (Where is my pencil?) To answer "nasaan" questions, you have to use "nasa" and the location of the thing or person that is being asked. • Nasa kahon (In the box or They are in the box.) • Nasa bahay (In the house or Amy is in the house.) • Nasa bag ko (In my bag or Your pencil is in my bag.) I know this answer doesn't cover all about this topic but I do hope that I've given you enough information that can be helpful in a way. Feel free to drop me a message for any clarifications. Cheers! Brian

nasaan, saan, sa --;all of these have the same meaning "where?" saan the root word and the most common word that literally translated as where. here is the order nasaan ;nasan ;nasa; saan; san ;sa nasaan ,nasan, saan,san you can use these words for everything. persons,place,things etc. for instance : Where is my slippers? Nasaan/nasan ang aking tsinelas? Saan/san ang aking tsinelas? however, you can't say Sa/Nasa ang aking tsinelas? it will become a little bit awkward and probably we misunderstood its real meaning, for me it will become "my slippers are 1?" because of "Sa" i will interpret it as "Isa" or in english number 1. we usually say "sa/nasa" for elite instances and it could be a preposition and for the answer that the question is where. for instance: A : Paki kuha nga yung tsinelas ko sa may pinto . Please get my slippers at the door. B: Sa ? / Sa may? (may is a preposition) where? A: "Sa" may pinto. / Nasa pinto at the door