Nandoon sa istante ang mga mansanas, pero nandito sa ref ang mga saging.

They are location words.

• nandoon = there
• nandito = here

In this sentence, they tell you where something is located:

• Nandoon sa istante ang mga mansanas = The apples are there on the shelf.
• Nandito sa ref ang mga saging = The bananas are here in the fridge.

These words are very common in everyday Filipino.

Filipino often puts the location or setting first, especially when telling where something is.

So instead of structuring it like English:

• The apples are on the shelf

Filipino naturally says something closer to:

• There on the shelf are the apples

That is why you get:

• Nandoon sa istante ang mga mansanas
• Nandito sa ref ang mga saging

This word order is normal and natural in Filipino.

Ang is a marker that highlights the main noun phrase of the clause.

Here:

• ang mga mansanas = the apples
• ang mga saging = the bananas

In this kind of sentence, ang marks the thing whose location is being identified.

So the pattern is roughly:

• location + ang + thing

Examples:

• Nasa mesa ang libro. = The book is on the table.
• Nandito ang susi. = The key is here.

Mga is the plural marker in Filipino.

So:

• mansanas = apple / apples, depending on context
• mga mansanas = apples
• saging = banana / bananas, depending on context
• mga saging = bananas

Filipino nouns usually do not change form for plural the way English nouns do. Instead, mga is added before the noun.

In everyday speech, mga is usually pronounced roughly like muh-NGA or nga depending on speed and region.

It is not pronounced the way an English speaker might guess from the spelling. The ng is the same sound you hear at the end of English sing, but here it can appear at the beginning of the syllable too.

So:

• mga mansanas ≈ muh-NGA man-SA-nás

You will hear slightly different reductions in real speech, but that is normal.

Sa is a location marker. In this sentence it means in, on, or at, depending on the noun that follows.

• sa istante = on the shelf / at the shelf
• sa ref = in the fridge

So sa is very common when talking about places or locations.

Because they play different roles in the sentence.

• sa istante marks the location
• ang mga mansanas marks the main thing being talked about

So:

• sa = location marker
• ang = main noun phrase marker

This difference is extremely important in Filipino grammar.

Pero means but.

It connects the two contrasting ideas:

• the apples are on the shelf,
• but the bananas are in the fridge.

It is one of the most common Filipino conjunctions.

Yes, it is very common in everyday Filipino.

Ref is a borrowed and shortened form of refrigerator. In casual speech, many Filipinos say:

• ref = fridge / refrigerator

So sa ref means in the fridge.

Yes. That is a very natural alternative.

• Nasa istante ang mga mansanas.
• Nandoon sa istante ang mga mansanas.

Both are natural, but they feel slightly different:

• nasa istante focuses directly on the location on the shelf
• nandoon sa istante adds a sense of there, on the shelf

Likewise:

• Nasa ref ang mga saging.
• Nandito sa ref ang mga saging.

Using nandito/nandoon makes the here/there contrast stronger.

Dito and doon mean here and there, but nandito and nandoon are commonly used when saying that something is located somewhere.

Compare:

• Dito. = Here.
• Doon. = There.
• Nandito ang susi. = The key is here.
• Nandoon ang bag. = The bag is there.

So in this sentence, nandito/nandoon sound very natural because the speaker is locating the apples and bananas.

Yes, you can.

That would be:

• Ang mga mansanas ay nandoon sa istante, pero ang mga saging ay nandito sa ref.

This is also grammatical. It is a more explicitly topic-first structure.

Compare the two styles:

• Nandoon sa istante ang mga mansanas...
  more location-first
• Ang mga mansanas ay nandoon sa istante...
  more noun-first

Both are correct. The version in your sentence sounds very natural in everyday speech.

Because ay is often omitted in normal conversation.

Filipino can use an ay structure:

• Ang mga mansanas ay nandoon sa istante.

But in casual and very natural speech, speakers often use:

• Nandoon sa istante ang mga mansanas.

So the original sentence is not missing anything important; it is simply using a common conversational structure.

No, the noun itself usually stays the same.

• mansanas = apple / apples
• saging = banana / bananas

Plural is normally shown by mga, not by changing the noun ending.

So:

• ang mansanas = the apple
• ang mga mansanas = the apples
• ang saging = the banana
• ang mga saging = the bananas

Because the speaker is contrasting two different locations from their point of view.

• nandoon = there, farther from the speaker
• nandito = here, closer to the speaker

So the sentence creates a clear contrast:

• the apples are there on the shelf,
• but the bananas are here in the fridge.

This here vs. there contrast is an important part of the sentence.

It is a commonly used borrowed word, and many Filipino words in daily speech come from Spanish or English.

Istante means shelf. Even if it is borrowed historically, you can treat it as a normal Filipino vocabulary word in modern usage.

So:

• sa istante = on the shelf

It sounds mostly everyday and conversational.

Clues include:

• nandito / nandoon instead of more formal-feeling alternatives
• ref instead of a longer word
• the natural spoken word order

It is exactly the kind of sentence you could hear in ordinary conversation.