Page 215 - Tagalog for Beginners: An Introduction to Filipino, the National Language of the Philippines

conjugated this verb. The first row shows the verb with subject focus and the
second row, the verb with object focus.

Completed Incompleted Contemplative Infinitive
bumili bumibili bibili gusto kong bumili
binili binibili bibilhin gusto kong bilhin

What many students find confusing is shifting between the use of the verb when
the focus is on the subject and when the focus is on the object.
For example, with “ano” (what) questions, we usually use the object focus.

TANONG : Ano ang binili mo?

What did you buy? (literally, What marker buy you?)
SAGOT : Blusa ang binili ko.

I bought a blouse. (literally, Blouse marker bought I.)
TANONG : Ano ang binibili mo?

What are you buying? (literally, What marker buying you?)
SAGOT : Blusa ang binibili ko.

I am buying a blouse. (literally, Blouse marker buy I.)
TANONG : Ano ang bibilhin mo?
What will you buy? (literally, What marker buy you?)

SAGOT : Blusa ang bibilhin ko. I will buy a blouse. (literally, Blouse marker
buy I.)
TANONG : Ano ang gusto mong bilhin?

What do you want to buy? (literally, What marker want you to buy?)
SAGOT : Blusa ang gusto kong bilhin.
I want to buy a blouse. (literally, Blouse marker want I to linker buy).

However, for sino (who) and saan (where) questions, the focus is on the subject
or the doer of the action.
Thus:
TANONG : Sino ang bumili ng blusa?

Who bought the blouse? (literally, Who marker bought marker blouse?)
SAGOT : Ako ang bumili ng blusa.
I was the one who bought the blouse. (literally, I marker bought marker
blouse.)

OR