Learn Hardcore Filipino: Ang luma mong aklat ay nasa ilalim ng lamesa.

Ang is a marker that usually points to the topic or focus of the sentence—often the equivalent of “the” in English for that focused noun phrase.

Ang luma mong aklat = The old book of yours / your old book
The part marked by ang is what the sentence is mainly “about.”

In Ang luma mong aklat ay nasa ilalim ng lamesa, the sentence is basically saying:
As for your old book, it is under the table.
So ang appears at the start because that whole phrase is the topic.

Why is the order luma mong aklat instead of something like mong luma aklat?

In Filipino, descriptive adjectives normally come before the noun, and short pronoun forms like -ng (mong) attach to the adjective or noun they modify.

luma = old
mo = your (you, singular, informal)
mong = mo + -ng linker (a combined form attaching to luma)

So:

luma mong aklat
- literally: old-your book
- natural English: your old book

The structure is:

[ADJECTIVE] + mong + [NOUN]
→ luma mong aklat (your old book)
→ bago mong telepono (your new phone)

Putting mong at the start (mong luma aklat) is ungrammatical.

What exactly is mong? How is it different from mo?

Mo is the informal singular “you/your” pronoun.

mo by itself:
- aklat mo = your book

But in Filipino, there is often a linker (-ng, na) between modifiers (like adjectives or possessors) and the nouns they describe. When mo follows a word that takes -ng, the two fuse:

luma + ng + mo → luma mong

So:

luma mong aklat = your old book
Pattern: [adjective] + mong + [noun]

mo = stand‑alone form
mong = mo fused with the linker -ng attached to the preceding word.

What does ay do in this sentence? Can I leave it out?

Ay is a linking word (inversion marker) often used in more formal or neutral speech. It roughly corresponds to the linking “is/are” when we put the topic first.

Ang luma mong aklat ay nasa ilalim ng lamesa.
→ Topic (Ang luma mong aklat) + ay
- comment (nasa ilalim ng lamesa)

In everyday, more conversational Filipino, you can drop ay and switch the order:

Nasa ilalim ng lamesa ang luma mong aklat.
(most common spoken style)

Here, we don’t use ay; we just put the predicate (location) first, then the ang-phrase.

So:

With ay: more formal / textbook:
- Ang luma mong aklat ay nasa ilalim ng lamesa.
Without ay, more natural in speech:
- Nasa ilalim ng lamesa ang luma mong aklat.

What does nasa mean, and how is it different from sa?

Sa is a general preposition/marker used for locations, directions, indirect objects, etc.
Nasa is a special form used before a location to mean “is/are at/in/on”.

sa
- location:
  - sa ilalim ng lamesa = under the table
nasa
- location:
  - nasa ilalim ng lamesa = is/are under the table

In this sentence:

ay nasa ilalim ng lamesa
→ is under the table

You generally use nasa right before a phrase that tells you where something is:

nasa bahay = is at home
nasa eskuwela = is at school
nasa ilalim ng lamesa = is under the table

Why is it nasa ilalim ng lamesa and not nasa ilalim sa lamesa?

The structure “under the table” is:

ilalim ng lamesa
- ilalim = underside / bottom / under
- ng = linker/“of” here
  → literally “bottom of the table” → “under the table”

So the pattern is:

nasa + [locative noun] + ng + [thing]
- nasa ilalim ng lamesa = is at the underside of the table

Sa doesn’t go after ilalim here. Using sa directly before lamesa would break the standard “X of Y” structure:

❌ nasa ilalim sa lamesa (ungrammatical in standard Filipino)
✅ nasa ilalim ng lamesa

Can I also say Sa ilalim ng lamesa ang luma mong aklat?

Yes, but note the difference:

Nasa ilalim ng lamesa ang luma mong aklat.
→ The form with nasa is the most natural for expressing location “is under the table.”
Sa ilalim ng lamesa ang luma mong aklat.
→ This is understandable and can appear in some contexts, but nasa is strongly preferred when you’re simply saying where something is.

If you keep the ay pattern:

Ang luma mong aklat ay nasa ilalim ng lamesa.
is natural.
Ang luma mong aklat ay sa ilalim ng lamesa.
can sound a bit marked or less natural in many contexts.

For basic “X is at/in/on Y”, nasa + location is your safest default.

Where is the word for “is” in this sentence?

Filipino often does not use a direct equivalent of “is/are” like English does. The linking function can be shown by word order, ay, or a verb like nasa.

In:

Ang luma mong aklat ay nasa ilalim ng lamesa.

the idea of “is” is carried by:

ay (linking topic and comment)
nasa (meaning “is/are at/in/on”)

You could loosely map it as:

Ang luma mong aklat (your old book)
ay nasa (is located)
ilalim ng lamesa (under the table)

What’s the difference between aklat and libro?

Both mean “book”, but:

aklat
- More formal/standard/native Tagalog word.
- Common in literature, formal writing, some education contexts.
libro
- From Spanish libro.
- Very common in everyday speech, more colloquial.

You could say:

Ang luma mong libro ay nasa ilalim ng lamesa.
and it would sound more casual, but still correct.

How would I say “Your old books are under the table”?

You mainly need to pluralize aklat:

Ang mga luma mong aklat ay nasa ilalim ng lamesa.

Explanation:

mga = plural marker
Ang mga luma mong aklat = Your old books
The rest stays the same.

Spoken-style variant without ay:

Nasa ilalim ng lamesa ang mga luma mong aklat.

Can I drop ang or mong? For example, just say Luma mo aklat?

No, not in standard Filipino.

You need an ang-phrase to mark the topic/focus or subject‑like noun phrase.
- ❌ Luma mong aklat ay nasa ilalim ng lamesa. (wrong without Ang)
- ✅ Ang luma mong aklat ay nasa ilalim ng lamesa.
You also need the linker between luma and mo when mo attaches to it:
- luma + ng + mo → luma mong
- ❌ luma mo aklat
- ✅ luma mong aklat

Correct minimal patterns are:

Ang luma mong aklat ay nasa ilalim ng lamesa. (formal/neutral)
Nasa ilalim ng lamesa ang luma mong aklat. (natural spoken)