@JohnD
I do not know if they teach aspect in Filipino subjects now. When I was still in school, it seemed to me like Filipino tenses were also just simply "pangnagdaan" (past), "pangkasalukuyan" (present), and "panghinaharap" (future). In my case and that of most of my classmates then, maybe not much information or details were necessary anymore for us to learn Filipino because we already speak it. Tagalog is the first language of almost all of us and Filipino is practically Tagalog.
Assuming that my understanding of aspect is correct, I think that in Filipino, it is understood or shown through a time cue and by changing the verb form. For example, using the present tense for the aspects:
Simple/Indefinite: NAGLALAKAD ako papunta sa tindahan. = I WALK to the store. (If I am saying this at the moment, it will be understood as habitual action and, therefore, in the simple present tense).
Perfect/Completed: NAKALAKAD ako papunta sa tindahan kahapon. = I HAVE WALKED/was able to walk to the store yesterday.
Progressive/Continuing: NAGLALAKAD ako papunta sa tindahan ngayon. = I AM WALKING to the store right now.
Perfect Progressive: NAGLALAKAD ako pupunta sa tindahan tuwing umaga mula pa noong isang taon. = I HAVE BEEN WALKING to the store every morning since a year ago.
The thing is, Filipino does not have the equivalent of the verb "to be", but aspect in English grammar heavily relies on that verb. When we translate a Filipino sentence into English, we just have to make use of the to-be verb whenever it is needed as dictated by English grammar. We are able to figure out which form of the to-be verb to use simply based on the time cue of the Filipino sentence. It is possible that this to-be verb now becomes a problem for English speakers when they try to make a back translation.
"When I was walking, I tripped over" = "Nang ako ay naglalakad, ako ay nadapa". "Naglalakad" is simple present tense and "nadapa" is simple past tense. From the perspective of a Filipino, the narrator could only be referring to a past event and the tripping over must have happened within the time the narrator was walking. That is all that we need to know and we understand it in Filipino in exactly the same way as you would understand that as "When I was walking, I tripped over" in English. In Filipino that sentence might just be like "As I walk, I tripped over", and the corresponding aspect would just naturally settle in.