Maybe this can help you -
owlcation.com/humani ties/Filipino-Cultur e-Showing-Respect-To -Elders
If it's only the "po" that you are asking about, the general guideline is not to overuse it. Using it once in a sentence is normally enough. Where to place it will depend on what other words make up the sentence.
For example: Siya po; Hindi po siya; Ito po ang alam niya; Hindi niya po/po niya ito alam; Kumain na po sila; Kumain na po ba sila?; Hindi na po sila kakain; Kakain pa lang po daw/daw po sila; Hindi na po daw/daw po sila kakain.
It may be daunting to a learner of Tagalog, but in reality, even if it is misplaced, the listener will still understand your intention to be respectful based on your body language and tone of voice.
Listening to Tagalog conversations or watching Tagalog movies can be helpful.
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