This is another use of the word "Ang" other than being a definite article often translated as "The". Let's break it down... sipag=diligence... magsaliksik=to research. "Sipag" in this context becomes an adverb because it modifies the verb "magsaliksik". Grammatically, it should be "MAsipag magsaliksik" = "research diligently". The sentence: Ang sipag magsaliksík ng kaibigan ko ^_^. The word Ang puts emphasis on how sipag/diligent the friend does his research. So your sentence can be translated to "How diligent my friend researches ^_^." (or in any sentence construction acceptable in English as long as it stresses the word sipag.) You use this sentence word order if you want to emphasize "the how". Formula: (Ang+ adjective in their root/base form) eg. Ang pangit! = How ugly! Ang bagal ng internet ko. = How slow my internet is. Ang liwanag, nakakasilaw. = So bright, it's blinding. "Sipag magsaliksík" is a parirala/fragment and doesn't express complete thought. Therefore you can't drop off "Ang" just like that. Hope you get it. :)

Ang sipag magsaliksík ng kaibigan ko. (literally means: "The diligence to research of my friend.") (subconsciously understood by native speakers as: "My friend is diligent in research.") ---Vocabulary--- ang: a topic marker in tagalog sipag: diligence magsaliksik: to research ng: a non-focus particle of the actor/goal and is also used as a possessive marker in tagalog kaibigan: friend ko: my ---Usage of SIPAG--- 1] as a NOUN Ang sipag at tiyaga ay nagdudulot ng biyaya. ("Hard work and perseverance brings blessings.") 2] as an ADJECTIVE Ang sipag niya. (literally means: "The diligence of him.") (subconsciously understood by native speakers as: "He is diligent.") Masipag siya. (literally means: "He is diligent.") (the prefix "ma" + the verb "sipag" = masipag.) (NOTE: "ma" is a prefix used to express the state or condition of the actor/verb, thus, it is an adjective.) ---Usage of the prefix MAG--- saliksik (noun): research or investigation *magsaliksik (verb): to research or to investigate **adding "mag" to a noun like "saliksik" makes it a verb. **as a verb, it implies that the "action started and terminated", thus, in your sentence it was used as the subject. To further understand the usage of the prefix "mag", you can view my answer on this thread: http://www.italki.com/question/199871 Hope that helps. Happy learning! (^_^)

"sipag magsaliksik", "sipag para/upang magsaliksik" are both right and mean the same... the word "sipag" is an adjective (not a noun) while you're right with the word "magsaliksik" which is a verb...

Um... Not really... because Ang sipag magsaliksík ng kaibigan ko ^_^ alone is already complete.

Oh well, I just checked with her... and she told me that it takes "para" or "upang", is that right? :) Ang sipag para magsaliksík ng kaibigan ko ^_^