Verb Reference: isip | Filipino Grammar

The root isip names the mind and supports several kinds of thinking: engaging in thought, considering a selected idea, having something occur to you, and deliberating carefully. English “think” also introduces opinions and assumptions, but Filipino often uses sa tingin ko or akala ko for those meanings rather than forcing every case into the isip family.

The core family

These forms are (neutral) in contemporary Filipino. Because isip begins with a vowel, the mag-/nag- and pag-/pinag- families preserve visible hyphens.

Family and function	Basic	Completed	Incompleted	Contemplated	Typical frame
Actor voice: think, devise, deliberate	mag-isip	nag-isip	nag-iisip	mag-iisip	ang thinker + ng idea/solution or tungkol sa topic
Patient voice: think about, imagine, intend a selected content	isipin	inisip	iniisip	iisipin	ng/ni thinker + ang content
Potential/experiential: come to mind, be conceivable	maisip	naisip	naiisip	maiisip	ng/ni experiencer + ang idea, or clausal content
Deliberative patient voice: think over carefully	pag-isipan	pinag-isipan	pinag-iisipan	pag-iisipan	ng/ni thinker + ang proposal/problem

These families overlap, but they are not interchangeable. Mag-isip presents the thinker doing cognitive work. Isipin selects content. Maisip presents an idea as entering or being available to the mind. Pag-isipan adds sustained deliberation.

Mag-isip: the thinker is pivot

Actor-voice mag-isip can describe thinking in general, devising something, or directing thought toward a topic.

Nag-iisip si Farah ng paraan para mabawasan ang gastos sa kuryente.

Farah is thinking of a way to reduce the electricity expense. (incompleted actor voice; neutral)

Nag-isip kami tungkol sa mungkahi bago kami sumagot.

We thought about the proposal before we answered. (completed actor voice; neutral)

In the first sentence, ng paraan is something being devised. In the second, tungkol sa mungkahi explicitly introduces a topic. Exclusive kami refers to the speakers' group without the addressee.

Isipin: selected content is pivot

Patient isipin selects a person, plan, consequence, or proposition held in mind. Compare a thinker-centered and content-centered clause:

Nag-isip si Farah ng bagong ayos ng tindahan.

Farah thought up a new layout for the shop. (actor voice; neutral)

Inisip ni Farah ang bagong ayos ng tindahan bago siya bumili ng estante.

Farah considered the shop's new layout before buying a shelf. (patient voice; neutral)

The first emphasizes generating an idea and selects Farah. The second selects the identifiable layout as content under consideration and marks Farah with ni. Voice affects the marker frame and can interact with a small lexical difference; it is not simply English active versus passive.

Lagi kong iniisip ang mga magulang ko kapag malayo ako sa bahay.

I always think about my parents when I am far from home. (incompleted/habitual patient voice; neutral)

The short pronoun ko is the thinker in an ng form; ang mga magulang ko is selected content. For more on this alignment, see patient voice.

💡

Use mag-isip ang thinker ng idea, but isipin ng thinker ang selected content. English “think about” does not tell you which Filipino voice to choose.

Maisip: an idea occurs or becomes conceivable

Naisip often translates “thought of,” “realized,” or “it occurred to.” It does not necessarily say that the thinker deliberately worked through a problem.

Naisip kong tawagan ang may-ari bago kami pumasok sa bakuran.

It occurred to me to call the owner before we entered the yard. (completed experiential form; neutral)

The linker -ng joins ko to the following complement: naisip ko + na tawagan surfaces naturally as naisip kong tawagan. The embedded action is the content that came to mind.

Wala akong maisip na maikling pamagat para sa ulat.

I cannot think of a short title for the report. (potential under wala; neutral)

This construction profiles the absence of an available idea. English uses “cannot,” but Filipino naturally combines existential wala with maisip.

Kapag naiisip ni Berto ang nangyari, tumatahimik siya.

Whenever Berto thinks of what happened, he becomes quiet. (recurring experiential meaning; neutral)

Pag-isipan: deliberate before deciding

Pag-isipan conventionally means to consider or think something over. It favors proposals, choices, consequences, and problems whose evaluation takes time.

Pag-isipan mo muna ang alok bago ka lumagda sa kontrata.

Think the offer over first before you sign the contract. (deliberative patient-voice command; neutral)

Pinag-iisipan pa ng pamilya kung lilipat sila sa ibang lungsod.

The family is still considering whether they will move to another city. (incompleted deliberation; neutral)

The second example selects an embedded kung question rather than a simple noun phrase. Pa shows that the deliberation continues. A quick passing thought would fit naisip better than pinag-iisipan.

Fuller repetition mag-isip-isip means to reflect or think things over, often with a moderating “give it some thought” nuance (informal/neutral). It is written with a hyphen because the lexical base is repeated; it does not mean maximal mental effort.

“I think” is not always iniisip ko

English uses “I think” for several distinct stances:

Intended meaning	Natural Filipino expression	Register
current mental activity	Iniisip ko ang problema.	neutral
opinion or assessment	Sa tingin ko, tama ang pasya.	neutral
assumption, sometimes corrected later	Akala ko, sarado ang opisina.	neutral

Sa tingin ko, mas praktikal ang unang plano.

I think the first plan is more practical. (opinion; neutral)

Using Iniisip ko na mas praktikal... instead would suggest an ongoing thought or consideration, not merely the speaker's settled opinion.

Nouns and fixed expressions

Bare isip means “mind,” “thought,” or understanding. Pag-iisip names the activity or faculty of thinking, while kaisipan can mean an idea, concept, or body of thought, often in (formal/academic) writing. Common expressions include nasa isip “on one's mind,” wala sa isip “not intended/not mentally present,” and bukas ang isip “open-minded.”

—Ano ang nasa isip mo? —Kung paano natin maihahatid ang mga kahon bago umulan.

—What's on your mind? —How we can deliver the boxes before it rains. (neutral conversation)

Common Mistakes

Marking selected content with ang after actor voice

❌ Nag-iisip si Ema ang bagong iskedyul.

Incorrect — nag-iisip selects Ema as pivot; use ng for something being devised.

✅ Nag-iisip si Ema ng bagong iskedyul.

Ema is devising a new schedule. (actor voice; neutral)

Keeping a si-marked thinker with patient voice

❌ Iniisip si Ema ang epekto ng pagbabago.

Incorrect — patient-voice iniisip requires a ni-form thinker.

✅ Iniisip ni Ema ang epekto ng pagbabago.

Ema is considering the effect of the change. (patient voice; neutral)

Omitting the hyphen before a vowel-initial root

❌ Magisip ka muna bago sumagot.

Incorrect standard spelling — mag- before vowel-initial isip requires a hyphen.

✅ Mag-isip ka muna bago sumagot.

Think first before answering. (actor-voice command; neutral)

Using an actor pronoun where the experiential family requires an ng form

❌ Naisip ako ang mas maikling ruta.

Incorrect — in this experiential frame, the idea is pivot and the experiencer uses ko.

✅ Naisip ko ang mas maikling ruta.

I thought of the shorter route. (completed experiential form; neutral)

💡

The root network separates deliberate thinking (mag-isip/isipin/pag-isipan) from an idea becoming mentally available (maisip), while opinions often use sa tingin ko instead.

Key Takeaways

Use mag-isip for thinker-centered activity and isipin for selected content.
Use maisip when an idea occurs or can be conceived, and pag-isipan for sustained deliberation.
Keep required hyphens in vowel-initial forms such as nag-iisip and pinag-iisipan.
Translate English “I think” by meaning: mental activity, opinion, and assumption use different Filipino constructions.

Now practice Filipino

Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.

Start learning Filipino →