Mataas ang marka ni Liza sa pagsusulit dahil ginagawa niya ang takdang-aralin gabi-gabi.

Filipino very often uses a predicate-first word order.

So Mataas ang marka ni Liza sa pagsusulit is literally structured more like:

High + the grade of Liza on the exam

In natural English, we usually say Liza’s score on the exam is high, but in Filipino, starting with mataas is completely normal.

You could also say:

Ang marka ni Liza sa pagsusulit ay mataas

That version is also correct, but the original predicate-first pattern is very common and natural.

Ang is a very important marker in Filipino. In this sentence, it marks marka as the topic of the clause.

So in:

Mataas ang marka ni Liza sa pagsusulit

the thing being talked about is ang marka ni Liza sa pagsusulit.

A simple way to think of ang is that it often marks the noun that is most central in the clause, though it does not always match the English idea of subject exactly.

Because Liza is not the main topic of that part of the sentence. She is showing possession: Liza’s grade.

• ni Liza = of Liza / Liza’s
• si Liza = used when Liza is the personal-name topic of the clause

So:

• ang marka ni Liza = Liza’s grade
• not ang marka si Liza, which would be ungrammatical

With personal names, Filipino often uses:

• si for the topic form
• ni for the genitive form

Sa pagsusulit means in the exam, on the test, or in the test context.

The preposition sa is very broad in Filipino. It can mean things like:

• in
• on
• at
• to

depending on context.

Here, sa pagsusulit tells you where or in what area the high grade applies: it is Liza’s grade on the exam.

Yes, often you can.

• dahil = because, a bit more neutral or formal
• kasi = because, very common in casual speech

So this sentence could also be said as:

Mataas ang marka ni Liza sa pagsusulit kasi ginagawa niya ang takdang-aralin gabi-gabi.

That sounds natural in everyday conversation.
The original with dahil feels a little more formal or written.

Not exactly in the English sense. Filipino verbs are usually better understood in terms of aspect, not tense.

Ginagawa is imperfective aspect. It often describes an action that is:

• ongoing
• repeated
• habitual

So ginagawa niya ang takdang-aralin gabi-gabi can mean something like:

• she is doing her homework
• she does her homework
• she keeps doing her homework

Because of gabi-gabi (every night), the meaning here is clearly habitual:
she does her homework every night.

This is a very common learner question because it involves voice/focus and case marking.

In the sentence:

ginagawa niya ang takdang-aralin

the verb is in a form that puts focus on the object/theme, and that matches ang takdang-aralin.

So the pattern is:

• ginagawa = object-focused/imperfective
• niya = the doer/actor in genitive form
• ang takdang-aralin = the focused/topic object

A different structure is:

gumagawa siya ng takdang-aralin

That is also possible, but it is built differently:

• gumagawa = actor-focused
• siya = topic actor
• ng takdang-aralin = non-topic object

Both can refer to doing homework, but the grammar is not the same.

Very roughly:

• ginagawa niya ang takdang-aralin = the homework is what she is doing
• gumagawa siya ng takdang-aralin = she is doing homework

Because the verb form ginagawa requires the actor to be marked in the genitive form.

So:

• siya = nominative/topic form
• niya = genitive form

In this clause:

ginagawa niya ang takdang-aralin

• ang takdang-aralin is the topic
• niya marks the person doing the action

If you changed the verb to an actor-focused form, then siya would be the natural choice:

Gumagawa siya ng takdang-aralin.

So the pronoun choice depends on the verb pattern.

Takdang-aralin is the standard Filipino word for homework.

It is a compound word:

• takda relates to something assigned or scheduled
• aralin relates to study or lesson

So the idea is something like assigned lesson/work, which becomes homework in natural English.

It is a very common school-related word.

Gabi means night or evening.

When you repeat it as gabi-gabi, it means every night or night after night.

This kind of repetition is common in Filipino and often gives a repeated or distributive meaning.

Examples:

• araw-araw = every day
• linggo-linggo = every week
• taon-taon = every year
• gabi-gabi = every night

So in the sentence, gabi-gabi shows that Liza does her homework regularly, not just once.

Filipino often does not need a separate verb like is/are in simple descriptive sentences.

So:

Mataas ang marka ni Liza sa pagsusulit

literally has no direct word for is, but it naturally means:

Liza’s grade on the exam is high.

This is normal in Filipino. The adjective mataas can function as the predicate without adding a separate copula.

That is why many Filipino sentences feel shorter than their English equivalents.