Nasa backpack ang kompas at mapa.

Nasa shows location. In this sentence, it means something like is/are in, on, or at.

So Nasa backpack ang kompas at mapa literally works like:

• Nasa backpack = in the backpack
• ang kompas at mapa = the compass and map

A natural English translation is The compass and map are in the backpack.

For a learner, it is usually best to treat nasa as a common location word used in sentences like this.

Filipino often does not use a separate verb like English is/are in simple identification or location sentences.

Instead, the structure itself shows the meaning:

• Nasa backpack ang kompas at mapa.

So Filipino does not need a separate word equivalent to are here. The location marker nasa already lets the sentence mean are in the backpack.

That word order is very normal in Filipino.

Filipino often puts the predicate first and the topic/subject later. Here, the location comes first:

• Nasa backpack = the location/predicate
• ang kompas at mapa = the thing being talked about

So the sentence is structured more like:

• In the backpack are the compass and map

You could also say:

• Ang kompas at mapa ay nasa backpack.

That is also correct, but Nasa backpack ang kompas at mapa sounds very natural and common.

Ang marks the topic/subject of the sentence.

In this sentence, the things being located are:

• ang kompas at mapa

So ang tells you that kompas at mapa is the noun phrase the sentence is about.

A useful way to think about it is:

• nasa backpack = where they are
• ang kompas at mapa = what is in that place

Because kompas at mapa is one combined noun phrase joined by at (and).

So:

• ang kompas at mapa = the compass and map

You do not need to repeat ang before both nouns.

You may sometimes see repetition for emphasis or style:

• ang kompas at ang mapa

But in a simple sentence, ang kompas at mapa is completely normal.

Because mga is usually used to make a noun plural, such as:

• mapa = map
• mga mapa = maps

But here you do not have multiple items of the same noun. You have two different nouns:

• kompas = compass
• mapa = map

So Filipino uses kompas at mapa rather than mga.

At means and.

So:

• kompas at mapa = compass and map

It joins the two nouns together into one phrase.

Yes. Backpack is a borrowed word and is very understandable in everyday Filipino.

Filipino uses many borrowed words, especially for modern objects. So a sentence like:

• Nasa backpack ang kompas at mapa.

sounds natural in casual modern usage.

Depending on the speaker, you might also hear other words for a bag, but backpack itself is fine.

Filipino does not have articles that work the same way as English the and a/an.

Instead, meaning is often understood from context and from markers like ang.

So English says:

• the compass and map

But Filipino simply says:

• ang kompas at mapa

You should not try to match English articles word-for-word.

Yes, that is also correct.

It means the same thing:

• Ang kompas at mapa ay nasa backpack.
• Nasa backpack ang kompas at mapa.

The difference is mostly in sentence style and focus.

• Nasa backpack ang kompas at mapa is a very natural predicate-first pattern.
• Ang kompas at mapa ay nasa backpack puts the topic first and uses ay, which can sound a little more formal or careful.

Both are good Filipino.

Not exactly.

• sa is a general location marker, often meaning in, on, at, to
• nasa is commonly used in sentences to show that something is located somewhere

In this sentence, nasa is the natural choice because the sentence is saying where something is:

• Nasa backpack ang kompas at mapa. = The compass and map are in the backpack.

For a beginner, it is helpful to learn nasa + place as a very common pattern for location sentences.