Sa halip na bumili ng mahal na regalo, sumulat tayo ng liham mula sa puso.

Sa halip na means instead of or rather than.

It introduces an alternative to what someone might normally do.

In this sentence:

Sa halip na bumili ng mahal na regalo...
= Instead of buying an expensive gift...

A very common pattern is:

sa halip na + verb
or
sa halip na + noun phrase

For example:

• Sa halip na umalis, naghintay siya. = Instead of leaving, he waited.
• Sa halip na kape, tsaa ang inorder ko. = Instead of coffee, I ordered tea.

Here, bumili is being used in an infinitive-like way: to buy / buying.

After sa halip na, Tagalog commonly uses this kind of verb form to express the action being contrasted.

So:

sa halip na bumili
literally works like
instead of buying

Even though bumili can also be a past form in other contexts, here it is not understood as bought. The structure sa halip na + verb makes it clear that it means buying / to buy.

mahal na regalo means expensive gift.

• mahal = expensive
• regalo = gift

The na here is a linker. It connects the adjective mahal to the noun regalo.

So:

• mahal na regalo = expensive gift

This na does not mean already here. It is just a grammatical connector.

A few more examples:

• mabait na bata = kind child
• malaking bahay = big house

Notice that sometimes the linker appears as na, and sometimes as -ng, depending on the sound at the end of the first word.

Yes. Mahal can mean different things depending on context:

• expensive
• dear / beloved
• love (as a noun or term of endearment in some contexts)

In mahal na regalo, it clearly means expensive, because it is describing a gift as something costly.

If it meant beloved gift, that would be a much less natural interpretation here.

So context tells you which meaning is intended.

In this sentence, ng marks the object of the verb.

So:

• bumili ng mahal na regalo = buy an expensive gift
• sumulat ng liham = write a letter

With actor-focus verbs like bumili and sumulat, the thing being bought or written is commonly marked by ng.

This is one of the most important uses of ng in Tagalog.

Also, be careful not to confuse this ng with the -ng linker in words like malaking. They are different grammar items, even though they look similar.

Here, sumulat tayo means let’s write.

This form can be confusing, because sumulat can also mean wrote in other contexts. Tagalog often relies on context to tell you which meaning is intended.

Why it means let’s write here:

• tayo includes the listener
• the whole sentence is making a suggestion or proposal
• the contrast with sa halip na bumili... strongly supports a hortative meaning

So:

sumulat tayo ng liham
= let’s write a letter

This is a very natural way to make a suggestion in Tagalog.

Tayo is the inclusive form of we. It includes both:

• the speaker
• the person being spoken to

That is exactly what English let’s does.

So:

• sumulat tayo = let’s write

If you used kami, it would exclude the listener, so it would not match the idea of let’s.

This is a very important distinction in Filipino:

• tayo = we, including you
• kami = we, not including you

Mula sa puso literally means from the heart.

• mula = from
• sa = a marker used here with the source phrase
• puso = heart

As in English, this expression means something is sincere, heartfelt, or genuine.

So:

liham mula sa puso
= a letter from the heart
= a heartfelt letter

It is both understandable literally and natural idiomatically.

Tagalog often does not need an indefinite article like English a/an.

So:

• ng mahal na regalo can mean an expensive gift
• ng liham can mean a letter

If you want, you can sometimes add isang for emphasis or clarity:

• ng isang mahal na regalo
• ng isang liham

But in many natural sentences, leaving it out is completely normal.

The given word order is natural, and it emphasizes the contrast first:

Sa halip na bumili ng mahal na regalo, sumulat tayo ng liham mula sa puso.

This puts instead of buying an expensive gift at the front, so the alternative is highlighted right away.

You could also rearrange it, for example:

Sumulat tayo ng liham mula sa puso sa halip na bumili ng mahal na regalo.

That is also understandable, but the original version sounds especially natural because the contrastive phrase comes first.

So the word order is not absolutely fixed, but the original sentence has a clear and effective emphasis.