magbili / nagbili - buy or sell?

[Pertinax]

A number of sources define "magbili" as to sell (versus bumili = to buy). E.g. this is the definition of "magbili" in the dictionaries of Carl Rubino (2002) and Leo English (1986). There are also sentences with "nagbili" in this sense in
Schachter & Otanes (1972): A Tagalog Reference Grammar
J Donald Bowen (1982): Beginning Tagalog: A Course for Speakers of English
Tsunekazu Moriguchi (2005): A typology of languages
E.g. Moriguchi translates:
nagbili si John ng mansanas = John sold an apple.

However, the two native Tagalog speakers that I have asked reject "nagbili" as flat-out ungrammatical. One Bisayan speaker from Agusan uses "nagbili" when speaking Tagalog, but in the sense of bought, not sold. Occurrences of "nagbili" on the internet seem to have the sense "bought", including this example from President Duterte (admittedly not a native Tagalog) FULL TEXT: President Duterte's State of the Nation Address 2017
ang gobyerno nagbili ng medisina ... It was not really a reckless purchase.

As far as I can make out, the root "bili" means (1) buying/selling price (2) sale (3) act of selling. Some derivatives (e.g. bumili) have the sense of buying, others (e.g. ipinagbili) have the sense of selling. How do users here understand "nagbili", if at all?

 

[Pertinax]

According to Ramos 1971: it should be noted that "magbili" and "umahit" are rarely used. Perhaps it is now rarer still: several more Tagalogs have confirmed to me that "nagbili" is "ungrammatical". But one Tagalog noted that it is common to hear "nag-" instead of "-um-" from Visayans speaking Tagalog, since Visayans apply "nag-" to their own verbs and many assume that it is equally sound to do so in Tagalog.

I think, then, that "nagbili", as used now (at least by non-Tagalogs) is far more likely to mean "bought" than "sold". This rather undermines the point being made by a number of grammar books. Does anyone still use it to mean "sold"?

 

[DotterKat]

This is one of those many thorny issues in Tagalog grammar in which the seemingly correct textbook formulation leads to some confusion. I do agree that magbili to mean to sell is colloquially unacceptable. It is best to use bili when buying something and benta when selling something.

 

[neealio]

Hello im still a beginner at Tagalog but i was wondering if it would be appropriate to use another affix like "in" as in "binili" to refer to something as bought or are their some affixes that are preferred.

 

[Pertinax]

You really need a dictionary to be sure which affixes each root accepts, and what the corresponding meaning is - though in most cases you can make a good guess. The affixes "mag-/nag-" (active) and "-in/-in-" (passive) are probably the most common verbal affixes. With "bili" the usual active form is "bumili", and the most common passive form "bilhin" ("binili").