Part 1 Your question, which may appear as simple, actually needs a lengthy answer to explain how “pag” is used. So brace yourself. :-)))) When it stands alone, “pag”, which is just the shortened version of “kapag”, functions as the conjunction “if”, or the adverb “when”, or the conditional “should”. Sometimes we use the word “kung” in its place. “Ibibili kita ng kotse pag/kapag/kung yumaman ako balang araw. = I will buy you a car if/when/should I become rich someday. The sentence you gave, “When you have studied, do the dishes”, may be translated as “Pag/Kapag natapos kang mag-aral, maghugas ka ng mga pinggan/hugasan mo ang mga pinggan” (“maghugas” – subject-focused, “hugasan” - object-focused). So, you are right, "pag" or "kapag" is used there as "when". However, we usually put “pagka” and “natapos” together and it becomes “pagkatapos” (then, afterwards), which would make that, “Pagkatapos mong mag-aral, ... . The “pag/kapag” before “natapos” and the “pagk(a)” in “pagkatapos” are the adverbs “when” and “after” that introduce the adverbial phrases in both sentences. Notice that when “natapos” was used as a separate word, “kang” (“ka” (you) + “ng) follows it, but when it is combined with “pag”, “mong” (“mo” (your) + “ng”) follows it. That’s because “natapos” still functions there as a verb – “after YOU have finished studying...” and for that reason you may remove “pag/kapag” and still correctly exclaim, “Natapos kang mag-aral!” = “You have finished studying!” However, in “pagkatapos”, the verb loses its identity and only becomes part of an adverbial phrase that needs to modify another verb – “maghugas” or “hugasan” in this case. Therefore, you may think of the “pagkatapos mong mag-aral” phrase as, “after finishing YOUR studying...”.

Part 3 “Mag” is one of those prefixes that make a verb out of a root word. “Pag”, on the other hand, when attached to a root word, usually converts that word to a noun or gerund. Examples: Root Word (RW): “kain” = eat Common Verb Forms (CVF): “kumain” (subject-focused) , “kainin” (object-focused) Noun/Gerund Form (N/GF): “pagkain” = (the act of) eating; food “Pag/Kapag kumakain siya, ang pagkain niya ay mabagal” = When he eats, his (manner of) eating is slow. – Though the second phrase may be understood as or translated to “he eats slowly”, the meaning of “pagkain” there still refers to the manner and does not function as a verb. RW: “dating” = arrive, come CVF: “dumating” = to arrive/come (s-f); “datnan” (o-f) N/GF: “pagdating” = coming; arrival “Kung sinabi niya na darating siya, hintayin nating ang pagdating niya.”. = If he said that he will come/arrive, let’s wait for his arrival/coming. – “pagdating” is now used as a noun or gerund RW: “alis” = go, leave, remove CVF: “umalis” = to go/leave (s-f); “mag-alis” (s-f) = to remove, “alisin” (o-f) N/GF: “pag-alis” = (the act of) leaving; departure; (the act of) removing, removal “Umalis na si Mary kahapon. Maraming nalungkot sa kanyang pag-alis” = Mary already left yesterday. Many were saddened by her departure/leaving. – “pag-alis” is now used as a noun or gerund. “Ang mag-alis ng mantsa sa puting damit ay mahirap. = To remove stain on a white dress is difficult. – The verb "mag-alis" is used in the infinitive. “Ang pag-alis ng mantsa sa puting damit ay mahirap, pero kailangan itong alisin” = (The act of) Removing/The removal of stain on a white dress is difficult, but it has to be removed. The last 2 examples show the difference in using “mag” and “pag”. Also these: “Mabilis kang maglakad” = You walk fast. “Mabilis ang paglakad mo” = The way you walk is fast.

Part 2 There are verbs, like “natapos” above, that lend themselves to the merging with “pag” and thereby lose their function as verbs to become only a part of an adverbial phrase. For example: Umalis (to go/leave): (ka)pag umalis ->pag-alis (when something leaves) - a hyphen is used when “pag” is attached to a word that starts with a vowel – “Sisikat ang araw pag-alis ng bagyo” = The sun will shine when the storm leaves. Dumating (to arrive/comes): (ka)pag dumating -> pagdating (when something arrives/comes) = “Mamahalin mo rin siya pagdating ng panahon = You will also love him/her when the time comes. Tumayo (to stand up) -> (ka)pag tumayo -> pagtayo (when something stands up) = “Pumalakpak ang mga tao pagtayo niya” = The people applauded when he/she stood up. Remember that “pag” in such cases retains its meaning as the adverb “when”. These “pag” words in adverbial phrases should not be confused with the same words that are used in another way, as you will see later. Difficulty may be encountered though in distinguishing if “pag” is being used as shown above or as it will be used in the succeeding explanations. Translating or understanding the sentence correctly would guide you on how it is being used. (to be continued) :-)

Part 4 At times, you may see “pag” followed by the repeated first syllable of the word it is attached to. Usually, that would translate to the gerund form of the word. Examples: “ang pag-alis ng mantsa sa damit” = the removal of stain on clothes “ang pag-aalis ng mantsa sa damit” = removing stain on clothes “Ang paglakad niya ay mabagal.” = His manner of walking is slow. “Ang paglalakad ay mabuti para sa ating kalusugan.” = Walking is good for our health. However, I don’t think that the repeated or unrepeated syllable is crucial in making a distinction in meaning. Context would prevail. There is also the use of “pag” at the beginning of a word, then an “in” or “an” is added at the end. You will see this in the last 2 examples below, each of which is just.another way of expressing the object-focused “in” or “an” form of a verb. But it is in these 2 examples that you will be able how the prefix “pag” is used to form a verb. “Mag-isip ka muna bago mo siya gawin” = Think first before doing it. (s-f) “Isipin mo muna bago mo siya gawin” = Think first before doing it. (o-f) “Pag-isipan mo muna bago mo siya gawin” = Give it some thought first before doing it. (o-f) “Pagkatapos mong mag-aral, paghuhugasan mo ang mga pinggan” = After studying, do the washing of the dishes. - This is the transformation of your sentence using a “pag verb”. Note the need for “do” in the translation. Again, it is only an alternative way of stating “hugasan”, the object-focused infinitive/imperative verb form of “hugas” (wash). Depending on the verb being used, sometimes the meaning resulting from using these “pag” and “in” or “an” affixes can deviate from that of its common verb form. Like, it’s possible that the object of the verb might have to change as a result. But that’s another story and may just be a more complicated matter to explain for now. :-)

Hi Adam, So three things: 1. The pag- prefix and the pag abbreviation of kapag are different things 2. Pag- can be both a noun prefix or a verb prefix 3. pag- and mag- verb prefixes are not interchangeable * Examples for point 1: Malamig ang panahon kapag umuulan. Malamig ang panahon pag umuulan. Both mean "The weather is cool when it's raining." Notice that "pag" here is not an affix. * Examples for point 2: Inaantay ko ang pagdating niya. (I am waiting for his arrival). -- pagdating here is a noun Aalis ako pagdating ni Nanay. (I'll leave when Nanay arrives). -- pagdating here is a verb * Examples/explanations for point 3: Mag- is a common verb prefix Pag- is a verb prefix that expresses a particular action. I'll copy an explanation below: "Pag- (or, in the case of mang-verbs, pang-) followed by a verb root means "when" plus the meaning of the verb" [Source: Beginning Tagalog: A Course for Speakers of English by Philippine Center for Language Study] Ex. Kumain tayo sa labas pagbalik ko galing U.S. (Let's eat out when I arrive from the U.S.) *** It seems that you are not the only who had this confusion about pag- as verb and pag as in "kapag". Did you read it in any book? Hope this helps! Let me know if you need more clarifications.