Learn Hardcore Indonesian: Saya masuk lewat gerbang sekolah pagi ini. - I entered through the school gate this morning.

masuk means “to enter.” It is generally intransitive, so it doesn’t take a direct object. Instead, you indicate where you enter by using a preposition (e.g. lewat, ke, dari). If you need a transitive form, you can use memasuki (e.g. Saya memasuki rumah).

What does lewat mean, and how is it different from melalui?

lewat here is a preposition meaning “through” or “via.” melalui is a more formal synonym. In everyday speech, learners often prefer lewat; in written or formal contexts, melalui is equally correct.
Example:

Saya masuk lewat gerbang sekolah.
Saya masuk melalui gerbang sekolah.

Why do we say masuk lewat gerbang sekolah instead of memasuki sekolah lewat gerbang?

Because masuk is intransitive and naturally pairs with lewat to show the path. memasuki is transitive (“to enter into”) and requires its object immediately after:

Correct: Saya memasuki sekolah.
You could add a prepositional phrase but it feels less idiomatic:
Less natural: Saya memasuki sekolah lewat gerbang sekolah.
To keep it smooth, native speakers say Saya masuk lewat gerbang sekolah.

How do we form compounds like gerbang sekolah in Indonesian?

Indonesian uses a head-modifier structure without linking particles. The head noun (main concept) comes first—gerbang—and the modifier (specifying noun) follows—sekolah—so gerbang sekolah literally reads “gate school,” i.e. “the school’s gate.”

Where should time phrases like pagi ini be placed in a sentence?

Time adverbials are flexible. You can begin with pagi ini or end with it. Both are correct:

Pagi ini, saya masuk lewat gerbang sekolah.
Saya masuk lewat gerbang sekolah pagi ini.
Front‐placement gives the time extra emphasis.

What does pagi ini mean exactly, and how is it different from just pagi?

pagi ini means “this morning,” specifying today’s morning. pagi alone means “morning” in general (e.g. Saya sarapan pagi = “I have breakfast in the morning”). If you want to pinpoint today’s morning, you add ini.

Can we drop saya and still be understood?

Yes. Indonesian often omits the subject when context is clear.

Masuk lewat gerbang sekolah pagi ini is perfectly understandable in casual speech.
Including saya simply makes it explicitly personal or more formal.

Why is there no verb tense marker for this morning’s action?

Indonesian verbs don’t conjugate for tense. Instead, you rely on time words (pagi ini, kemarin, nanti) or context to indicate when an action took place. Here, pagi ini clearly marks the action as having happened this morning.