Punan mo ito.

• punan = fill / fill in
• mo = you (the person being told to do it)
• ito = this

So the structure is basically:

verb + you + this

That verb-first order is very normal in Filipino.

Punan is the plain -an form of the verb, built from puno plus -an.

In practical learner terms, you can think of punan as a form used for filling a space, place, container, blank, or form.

In Punan mo ito, it is being used as a command.

Because this sentence uses a verb pattern where the doer is expressed with mo.

A simple way to remember it:

• ikaw = standalone you
• ka = you in many actor-focused sentences
• mo = you in many object-focused commands like this one

So after punan, mo is the natural form.

Because mo is a short pronoun that normally goes very early in the sentence, usually right after the first word.

So:

• Punan mo ito = natural
• Punan ito mo = not natural

This is a very common Filipino word-order pattern with short pronouns.

Ito means this.

It usually refers to something near the speaker.

Compare:

• ito = this (near me)
• iyan = that (near you)
• iyon = that (far from both of us)

So Punan mo ito is telling someone to fill this one / this thing.

No. It can be used both:

• literally: fill a container, box, space, etc.
• figuratively/practically: fill in a form, blank, field, or document

So depending on context, it could mean things like:

• Fill this.
• Fill this up.
• Fill this in.
• Complete this.

It is direct and neutral-casual. It is fine in everyday situations, instructions, or when speaking casually.

If you want to sound more polite, you could say:

• Paki-punan mo ito.
• Paki-punan po ito.
• Punan po ninyo ito.

Adding po makes it more respectful.

Mo is normally for one person.

If you are speaking to:

• one person casually: Punan mo ito
• more than one person, or more politely: Punan ninyo ito
• more politely with respect: Punan po ninyo ito

So yes, mo is basically singular here.

A rough English-style guide is:

poo-NAHN mo ee-TOH

Notes:

• punan: stress is on the second syllable
• mo: short, like moh
• ito: stress on the last syllable

Filipino pronunciation is generally clean and vowel-based, so each vowel is usually clearly pronounced.

Yes, if the object is already obvious from context.

For example, if both people are looking at the same form or container, Punan mo may be enough.

But Punan mo ito is clearer because it explicitly says this.