This is the polite version of the Tagalog word for ‘yes.’

 The word po is often used when talking to someone much older than you.

Compare the following sentences:

Ewan ko.

I don’t know. (casual)

Ewan ko po.

I don’t know. (respectful)

Salamat sa tulong mo.
Thank you for your help. (casual)

Salamat po sa tulong ninyo.
Thanks to your help. (respectful)

The following is a special case of word formation:

Yes. (casual)

Yes. (respectful)

Sometimes, ho is substituted for po.

Opo. = Oho.

Salamat po. = Salamat ho.