"Po" never occur at the beginning of a sentence. They usually come after a verb. Sometimes there is an enclitic pronoun after the verb and so "po" comes after that. In standard, formal Tagalog the only enclitic pronoun that "po" would follow is just the first person pronoun ko. The 2nd person pronouns "mo" and "ka" do not co-occur with "po" and "ho." Example: Ginawa ko po ito. “I did this, sir/ma’am.” In informal, colloquial Tagalog "niya" and ‘nyo (the short form of ninyo) behave like enclitic pronouns and therefore they go before "po" and "ho." Example: Ginawa niya po ito. (As opposed to Standard Tagalog Ginawa po niya ito.) “He/she did this.” Enclitic particles then follow enclitic pronouns. Keep in mind that "po" is just one of several enclitic particles. When there are more than one enclitic particles in a sentence, they have to be ordered in a particular way according to their class, as defined by Paul Schachter & Fe T. Otanes in their 1972 work Tagalog Reference Grammar. According to section 6 of Schachter and Otanes, there are four classes of enclitic particles: Class 1: na and pa Class 2: man Class 3a: ba, din, kasi, ho, lamang, nga, po Class 3b: daw, muna, naman Class 4: kaya, pala, sana, tuloy, yata This means that the following sentences are grammatical: Wala pa po si Juan. “Juan is still not around, sir/ma’am.” Tumawag na po yata si Maria. “I think Maria has already called, sir/ma’am.” Whereas these ones are not: *Wala po pa si Juan. *Tumawag na yata si Maria po. It does get a little more complex. Schachter and Otanes explain: “Those class 3 particles listed in subclass 3(a) never follow a class 4 particle; those listed in subclass 3(b) may follow a class 4 particle.”

ho and po is a sign of respect used at the end of the sentence. Both shows respect but po have higher regards. example. if someone called you which you have the most respect you can answer po or opo if u say yes on the other hand to someone you have less respect you can say ho or oho of u mean yes...

the word "po" is use to give respect specialy to someone who's older than you. mother=rose halika dito(come here) Rose=Bakit po! cowboy...

Furthermore, within class 3, they explain that the following order is preferred: nga + din + lamang/lang + daw + po (ho) + ba + muna + naman + kasi Examples: Ito lang po. “Just this, sir/ma’am.” Maingay daw po kasi sa salas. “Because it’s supposedly noisy in the living room, sir/ma’am.” Nakauwi na po ba kayo sa Pilipinas noong Pasko? “Were you able to go home to the Philippines during Christmas, (sir/ma’am)?”

Using the word "po or opo" is in polite manner specially when you have some conversation with the elders. While "ho" is informal, using po and opo is a good way to pleased people. Here are some example. 1. What do you want? - Ano po ang gusto ninyo? or Ano po ang gusto nila? 2. I need your help. - Kailangan ko po ang inyong tulong. 3. Are you ready to go? - Nakahanda na po ba kayong lumisan? 4. Yes - Opo