Question: Focus

The verb “binigyán” is an Object-Focus (OF) verb.
A1. “Binigyán KO ng karné ANG aso sa liwasan.” = ANG aso sa liwasan ay binigyan KO ng karne. = I gave meat to THE dog at the plaza.We can replace “binigyan” in that sentence with “magbigáy” a Subject-Focus (SF) verb.
B1. “Nagbigay AKO ng karne SA aso sa liwasan.” = AKO ay nagbigay ng karne SA aso sa liwasan. = I gave meat TO the dog at the plaza.Notice that in A1 (with an OF verb), the Actor is “KO (I)”, an adjective pronoun. In B1 (with a SF verb), the Actor becomes “AKO (I)”, a Subject Pronoun.Also, in A1 the Indirect Object “aso” is preceded by “ANG (THE)”, which marks “aso” as the Subject of the sentence. In B1, the Indirect-Object dog remains as is and is preceded by the preposition “SA (TO)”.The pattern remains the same even when the subjects are different:
OF: Binigyan NI Sam ng karne ANG aso SA liwasan. = Sam gave meat TO the dog AT the plaza.
SF: Nagbigay SI Sam ng karne SA aso SA liwasan. = Sam gave meat TO the dog AT the plaza. OF: Binigyan NINYO ng karne ANG aso SA liwasan. = YOU gave meat TO the dog AT the plaza.
SF: Nagbigay KAYO ng karne SA aso SA liwasan. = YOU gave meat TO the dog AT the plaza.OF: Binigyan NG pinsan ko ng karne ANG aso SA liwasan. = My cousin gave meat TO the dog AT the plaza.
SF: Nagbigay ANG pinsan ko ng karne SA aso SA liwasan. = My cousin gave meat TO the dog AT the plaza.What if the verb is “puntahan (go to something)”? (The SF verb counterpart of the OF verb “puntahan” is “magpunta/pumunta”.) The same things will happen if the verbs used are “puntahan” and “magpunta/pumunta”.
OF: Puntahan NATIN ANG mall. = ANG mall ay puntahan NATIN. = Let US go TO the mall
SF: Magpunta/Pumunta TAYO SA mall. = TAYO ay magpunta SA mall. = Let US go TO the mall. OF: Pinuntahan NI Sam ANG mall. = ANG mall ay pinuntahan NI Sam. = Sam went TO the mall.
SF: Nagpunta SI Sam SA mall = SI Sam ay nagpunta SA mall. = Sam went TO the mall.

In the SF sentences, the “sa” indicates the Object (of the preposition) and is also replaced by “ang” when the object becomes the subject of a sentence using an OF verb. Hence, the “sa” preposition is not the indicator of the subject of the sentence.

@Juantutri Good info! I'd just add that in most learner materials for foreigners, they'd call "bigyan" a locative/location/directional focus verb...as opposed to ibigay, which would be referred to as an object focus verb. Usually, if the "sa" phrase in the actor focus counterpart (-um-/mag-) becomes an "ang" phrase in a verb, you'd call that verb a location focus verb, instead of an object focus verb. Just trying to clarify if people see other terms elsewhere. Some people have preferred we would just use the terms "actor focus" and "non-actor focus" to simplify things,...I can see some benefits to that, too...although it's nice to have a term to differentiate things like bigyan and ibigay.

@jkos
When I started explaining Tagalog grammar to learners, I knew nothing about Focus because I, or at least as far as my generation is concerned, never learned our grammar that way. I suppose our school system’s approach was different because we were already Tagalog speakers from the start.Understanding the basic classification of Focus as either Subject or Object was easy for me because all it meant was to determine the subject of the sentence. Then when I encountered the terms locative, benefactive, etc., I looked them up but found them confusing. For example: “Nagpunta si Sam SA mall.” - Yes, that “sa mall” makes it locative, but the sentence uses a subject/actor-focus verb. When an object-focus verb is used instead, the sentence becomes “Pinuntahan ni Sam ang mall”. Since the “mall” is a location, then I can still imagine why it’s locative.“Nagbigay si Sam ng karne SA aso.”/”Binigyan ni Sam ng karne ANG aso.” – This now puzzles me because I am no longer sure if it’s locative/directional or benefactive.If we’d use the verb “ibigay”, the sentence becomes “Ibinigay ni Sam ANG karne SA aso”. The subject this time is the Direct Object “karne”. Yet, I still can’t decide if it’s locative/directional or benefactive, or just plain object (but then the dog is also an object). 😵Maybe it’s just me, but my being confused deters me from explaining focus using those other terms. 😟 I, therefore, playing it safe just stop at the first fork in the road – subject/actor or object focus. 😅I also agree that it will be simpler to just refer to Focus as either Actor or Non-Actor and shall be using them henceforth.

@Juantutri
Thank you for the explanation! My question was based around my brain always going to "sa" when thinking of the receiver of something regardless of the verb used / subject of the sentence.
I understood in a sentence with a conjugation of "Bigyan", I needed the giver to be ko / nya / ni / etc. but would be quick to label the first object with "ang" even if that wasn't the subject. It makes more sense why there is the locative/location/directional focus note on certain verbs.
I love the nuance but it can be difficult to corral!!