May minuto ng tawag ang promo.

Here, may expresses existence or possession. In the pattern May X ang Y, it usually means Y has X.

So in this sentence, may tells you that the promo has or includes some minuto ng tawag.

That is a very common Filipino sentence pattern.

With may, the thing that exists or is possessed often comes first: May X ang Y = Y has X

So:

• May minuto ng tawag ang promo.
• literally: There are call minutes, the promo
• natural English: The promo has call minutes.

Filipino does not always put the topic first the way English usually does.

Ang marks the main topic or subject-like noun in the sentence.

In a may sentence, the ang phrase is often the thing being talked about as the possessor:

• May pera ang babae. = The woman has money.
• May minuto ng tawag ang promo. = The promo has call minutes.

So ang promo is the item that has the call minutes.

Here, ng connects minuto and tawag in an of-type relationship.

So minuto ng tawag is literally something like minutes of call. In natural English, we would usually say call minutes.

This is a common Filipino way to connect nouns:

• bahay ng kaibigan = house of a friend / friend’s house
• oras ng klase = time of the class / class time

Because tawag here is being used as a noun, not a verb.

• tawag = call (noun)
• tumawag = to call (verb)

In minuto ng tawag, the word tawag names the type of minutes: call minutes.

Filipino often does not mark plural unless it is important to do so.

A noun can stay in its basic form even when English would use a plural:

• may libro can mean there is a book or there are books, depending on context
• minuto can refer to minute(s), especially in a measure-like expression

So minuto ng tawag does not have to include mga. The context can already make it clear that more than one minute is meant.

Yes. That is also grammatical.

Compare these:

• May minuto ng tawag ang promo.
• Ang promo ay may minuto ng tawag.

Both can mean the same thing. The difference is mainly in structure and emphasis:

• May minuto... puts the existence of the minutes first.
• Ang promo ay may... starts with the promo, which may feel more like English.

All three can express existence or possession, but they are used a little differently.

• may — the most common form before a noun
• mayroon — fuller form, often a bit more formal
• meron — very common in speech, more conversational

Before a noun, may is usually the most natural:

• May minuto ng tawag ang promo.

So in this sentence, may is the normal choice.

Yes, in everyday Filipino, promo is very common. It is a borrowed word, ultimately from English promotion, but in the Philippines it often means a special offer, package, or deal, especially for mobile load, data, texts, and calls.

So ang promo naturally means the promo offer/package.

It is doing both at the same time.

The word may basically says there exists something, but when you add an ang phrase after it, the whole sentence often works like possession:

• May kotse ang kapitbahay. = The neighbor has a car.
• May minuto ng tawag ang promo. = The promo has call minutes.

So grammatically it comes from an existence pattern, but in meaning it often works like has/have in English.