Learn Hardcore Filipino: Mas mabilis ang tren kaysa sa kotse.

Mabilis is an adjective meaning “fast/quick.” It doesn’t change for number or gender. It can also function adverbially (see below). When it directly modifies a noun, add a linker: mabilis na tren (“a fast train”).

What does ang do in this sentence?

Ang marks the topic/subject phrase and also works like a definite article. Ang tren can mean “the train,” and in generic statements it can refer to a whole category (“trains in general”).

What does kaysa sa mean, and is the sa necessary?

Kaysa means “than.” With nouns, standard Filipino uses kaysa sa: kaysa sa kotse (“than a/the car”). In casual speech many speakers drop sa and say kaysa/kesa kotse, which is widely understood but less formal.

When do I use kaysa sa vs kaysa kay?

Use:

kaysa sa before common nouns and pronouns: kaysa sa kotse, kaysa sa akin/iyo/kanya/amin/inyo/kanila.
kaysa kay before personal names or titled persons: kaysa kay Maria, kaysa kay Dr. Reyes. Tip: With pronouns, use the oblique forms after sa: sa akin, sa iyo, sa kanya, etc.

Can I change the word order?

Yes. Common variants:

Mas mabilis ang tren kaysa sa kotse. (neutral)
Mas mabilis kaysa sa kotse ang tren. (emphasis on the comparison)
Ang tren ay mas mabilis kaysa sa kotse. (more formal/written style using ay) All are correct.

How would I say “Trains are faster than cars” explicitly in the plural?

Add the plural marker mga:

Mas mabilis ang mga tren kaysa sa mga kotse. The original singular also works generically.

How do I say “as fast as”?

Use the equality pattern kasing- + adjective + ng + compared thing:

Kasingbilis ng tren ang kotse. (“The car is as fast as the train.”) You can also flip it: Kasingbilis ng kotse ang tren.

How do I say “the fastest”?

Use the superlative prefix pinaka-:

Pinakamabilis ang tren (sa lahat). (“The train is the fastest [of all].”) To name the set explicitly: Pinakamabilis ang tren sa mga nabanggit.

Can mabilis directly modify a noun?

Yes—use the linker:

mabilis na tren (“a fast train”)
mabilis na kotse (“a fast car”) Linker rule: use -ng after a vowel or -n (e.g., maganda + -ng → magandang kotse), and na after other consonants (e.g., mabilis na tren).

Is mabilis also an adverb (“quickly”)?

Yes. Filipino often uses adjectives adverbially. Mark the adverb with nang when needed:

Tumakbo siya nang mabilis. (“He/She ran quickly.”) In comparisons: Mas mabilis tumakbo si Ana kaysa kay Bea.

Is it okay to say kesa instead of kaysa?

Yes. Kesa is a very common variant of kaysa, especially in casual speech: Mas mabilis ang tren kesa sa kotse. In formal writing, kaysa is preferred.

Do I always need ang? Can I say “Mas mabilis tren …”?

In standard Filipino, keep the ang marker: Mas mabilis ang tren … Dropping it happens in headlines or very casual speech, but it’s not standard in full sentences.

How do I say “slower” or “less fast”?

Use the opposite adjective or a negative equality:

Mas mabagal ang kotse kaysa sa tren. (“The car is slower than the train.”)
Hindi kasingbilis ng tren ang kotse. (“The car isn’t as fast as the train.”)

Are tren and treno both correct?

Both are used. Tren is the standard Filipino form; treno is a widely used variant in Tagalog conversation. Either will be understood. For “car,” kotse is the common word; awto exists but is less common.

Can I compare actions instead of nouns?

Yes. Compare verbal nouns or bare verb forms:

More formal: Mas mabilis ang pagsakay sa tren kaysa sa pagmamaneho.
Colloquial: Mas mabilis sumakay ng tren kaysa magmaneho.

Any pitfalls with names or kinship terms?

When the compared item is a person’s name or a kinship title used as a name, use kaysa kay:

Mas mabilis si Juan kaysa kay Pedro.
Mas mabilis siya kaysa kay Tatay. But with pronouns, use kaysa sa + oblique pronoun: kaysa sa kanya, kaysa sa akin, etc.