Learn Hardcore Filipino: Si Kuya ay sumulat ng plano para sa bagong proyekto sa paaralan. - My older brother wrote a plan for the new project at school.

Si is a marker that shows the focus/topic is a specific person’s name or title. It roughly corresponds to "the" in "the one we're talking about is...".

Si is used before:
- Personal names: Si Maria, Si John
- Kinship titles used as names: Si Kuya, Si Ate, Si Nanay

In Si Kuya ay sumulat…, Si Kuya is the topic of the sentence – the person we’re talking about.

What does Kuya mean exactly? Is it just "older brother"?

Kuya literally means older brother (of a speaker), but in real usage it’s broader:

Within a family:
- You call your own older brother Kuya instead of using his name:
  - Kuya, tulungan mo ako. – “Big brother, help me.”
As a respectful address to a slightly older male:
- Used for a man a bit older than you, even if he’s not your real brother:
  - A teenager might call a man in his 20s Kuya.
As if it were a name in sentences:
- Grammatically it’s treated like a name:
  - Si Kuya ay sumulat… – “Kuya wrote…”

So in the sentence, Si Kuya can mean:

“My older brother” (if context is family), or
“Kuya” as a respectful way to refer to that older male.

Why is there an ay after Si Kuya? Is it necessary?

Ay is an inversion marker used in a more formal or written style. It lets you put the topic first, then the comment about that topic.

Pattern: [Topic] ay [rest of the sentence]
- Si Kuya ay sumulat ng plano…
  Literally: “As for Kuya, (he) wrote a plan…”

Is it necessary?
No. In everyday speech, Filipinos more often say:

Sumulat si Kuya ng plano para sa bagong proyekto sa paaralan.

Both are correct.

With ay: more formal, bookish, or careful speech.
Without ay: more conversational and common in daily talk.

Can I change the word order? For example, is Sumulat si Kuya ng plano… also correct?

Yes, it’s very natural and actually more common in speech:

Sumulat si Kuya ng plano para sa bagong proyekto sa paaralan.

Both mean the same thing:

Si Kuya ay sumulat… – topic-fronted, formal-ish.
Sumulat si Kuya… – more typical spoken word order: Verb + Subject + Object.

Filipino is a verb-initial language in everyday conversation, so starting with Sumulat feels normal for most speakers.

What does sumulat mean in terms of tense/aspect? Is it past tense?

Sumulat is the completed aspect (perfective) of the verb sulat (“to write”) in its actor-focus form.

sumulat – wrote / has written (completed action)
sumusulat – is writing / used to write (incomplete or ongoing)
susulat – will write / is going to write (future)

So in this sentence:

Si Kuya ay sumulat…
→ “Kuya wrote a plan…” (the writing is done)

If you wanted to say “Kuya is writing a plan…”, you’d use:

Si Kuya ay sumusulat ng plano…

Why is it ng plano and not ang plano? What does ng do here?

In actor-focus sentences (where the doer is the focus), ng marks the direct object (the thing being acted on).

Si Kuya – actor/focus (marked with si)
ng plano – object (the thing written)

Compare:

Sumulat si Kuya ng plano. – “Kuya wrote a plan.”
Isinulat ni Kuya ang plano. – “The plan was written by Kuya.” (object-focus)

So here, ng plano tells us:

“plan” is the thing being written,
and it’s not being highlighted as the main focus; Kuya is.

There’s no “a” before “plan.” How do you say “a plan” in Filipino? Why just plano?

Filipino doesn’t use articles exactly like “a/an/the” in English.

Indefiniteness (“a/an”) and definiteness (“the”) are usually shown by markers like ang, si, ng rather than separate words like “a.”

In sumulat ng plano:

ng
- plano often corresponds to “a plan” or “the plan”, depending on context.
  The sentence doesn’t strictly force “a” vs “the.”

If you want to make “a plan” very explicit, you can say:

sumulat ng isang plano – “wrote a plan” (emphasis on “one plan”)

But sumulat ng plano is the most natural default.

What does para sa mean in para sa bagong proyekto? How is it used?

Para sa means “for” (intended for / in favor of / on behalf of).

Structure:

para sa + thing/place
- para sa bagong proyekto – “for the new project”
- para sa school – “for the school”

It marks the beneficiary or purpose:

Sumulat si Kuya ng plano para sa bagong proyekto.
– “Kuya wrote a plan for the new project.”

Contrast it with:

sa alone, which often marks location, time, or a general relation:
- sa paaralan – “at school / in school”

What’s the difference between para sa and para kay?

Both mean “for”, but they differ in what follows them:

para sa – used before common nouns / things / places
- para sa bagong proyekto – for the new project
- para sa paaralan – for the school
para kay – used before personal names or persons
- para kay Maria – for Maria
- para kay Kuya – for Kuya
- para kay Teacher Ana – for Teacher Ana

So:

sumulat ng plano para sa bagong proyekto – wrote a plan for the new project (a thing)
sumulat ng plano para kay Kuya – wrote a plan for Kuya (a person)

Why is it bagong proyekto and not just bago proyekto? What does the -ng do?

Bago means “new”. When an adjective comes before a noun, Filipino usually uses a linker to connect them. For words ending in a vowel (like bago), the linker is -ng attached directly:

bago + -ng + proyekto = bagong proyekto – “new project”

A few patterns:

Vowel-ending: bago + -ng → bagong proyekto
Consonant-ending: mabilis + na → mabilis na kotse (“fast car”)
Word ending in n: often drop the n and add -ng
- maganda + -ng → magandang bahay (“beautiful house”)

So the -ng here is just the grammatical linker, not part of the base word.

Does sa paaralan mean “at school” or “of the school”? What is it modifying?

Sa paaralan literally means “at/in the school” or simply “in school / at school.”

In para sa bagong proyekto sa paaralan, there are two main natural readings:

Project that takes place at school / belongs to the school
- “a plan for the new project at school”
- Here, sa paaralan is closely linked to bagong proyekto.
Wrote it while at school (location of the writing)
- “Kuya wrote a plan at school for the new project.”
- Here, sa paaralan attaches more to sumulat.

Without extra context, both are possible; most readers will lean toward “the new school project,” i.e., the project is related to the school.

Is there any difference between paaralan and eskwela / eskwelahan?

All relate to “school”, but with different flavors:

paaralan
- More formal/standard Filipino
- Derived from the root aral (“to study/learn”)
- Common in formal writing, government, education contexts.
eskwela / eskwelahan
- Borrowed from Spanish escuela
- Sounds more colloquial in many contexts:
  - eskwelahan – literally “school building / school place”

In your sentence, sa paaralan is perfectly natural and slightly more formal/neutral.
You might also hear:

sa eskwelahan – “at the school” in casual speech.