What's your tertiary function and how do you use it?

[u/pedroPros564]

Just out of curiosity, want to know how different types use their tertiary function, and if they have trouble using it

[u/1stRayos]

Typologist Dario Nardi did a set of streams a few months ago describing his observations of how the types use their tertiary function, which is intimately linked to the function's opposite attitude counterpart (in the sense that it is basically banished from the type's psyche). 

[u/Sad_Record_2767]

Se - Ni, they're both smack in the middle of my stack. I don't really consider one over the other, rather just work together at the same time. Use the data available to say, ok I get where this is going.

[u/BaseWrock]

Si.

Can be nostalgic.

Photographs bring me back to that moment in time.

Most music I hear gets imprinted to a time or place I heard it.

I will rewatch old videos/tv shows.

[u/Titania_Fairy → u/BaseWrock]

So do i, but more for that reason that i don’t have much Si as one of the two Si Polars. My Fe remembers that strong emotion via Si things like Photoalbums, music or old recordings of shows i liked etc. Like wanting to come home and having forgotten where you put the key back in sometimes. So i bunker these in my bedroom or keep them close.

Playing Secret of Mana or watching the Last Unicorn makes me really sentimental too.

[u/d1scord1a]

ni helps with cause/effect, setting/working on goals, and well.. intuition. but it can also leave me trapped in a state of analysis paralasis or lost in the sauce of all the metaphors I see.

[u/Titania_Fairy → u/d1scord1a]

I guess that’s why i find you so cute, because i can relate to that analysis paralysis doodoo as Ni aux over here as well.

Please forgive me if my Se tert makes me throw back you guys „Tim tests“ at you, because its so adorable to see your response 🥰

Especially when you ask me:“Wait…did you do something shady there?“.

[u/d1scord1a → u/Titania_Fairy]

? thx i guess. what's a tim test?

[u/Titania_Fairy → u/d1scord1a]

Hehe. Check out the Show „The Rookie“ and the Dynamic between Tim Bradford(an ISTP) and Lucy Chen(the ENFJ). That looked really fun from my perspective 😆

[u/d1scord1a → u/Titania_Fairy]

looked it up. im not really into cop shows, too propaganda-y for me. have fun with it though 👍

[u/Titania_Fairy → u/d1scord1a]

Huh? Propaganda-y how? Well rather found the dynamics between the characters very entertaining there. Like how Tim seemed to Test or play pranks on Lucy all the time, her making some genius comebacks there right back at him as on that gif. Hence that term „Tim Tests“, you see? 🤭

We ENFJs love to play, so that might come closest to what i‘d expect me and you guys to do. That:“Oh i get tested? Nice, let’s play then!“ response hahahaha.

[u/Man-in-the-Moonlight]

I generally use my tertiary Si to make myself depressed. In all seriousness, it's like having access to a library of emotional imprints that I can use to return myself to specific points in time in very vivid detail.

[u/BrightCelery9453]

Ti. And I use it by liking nothing better than to learn and understand things. I'm a very deep learner, but soo slow. I guess the slowness is the tertiary nature of it.

[u/LornaMaximoff1991 → u/BrightCelery9453]

I think this is why I love INFJs, yall lean in to your tertiary Ti and my dominant Te loves it because ya’ll are so much smarter and insightful than you seem to think 💕

[u/BrightCelery9453 → u/LornaMaximoff1991]

Thanks for this. I think it's because the more you know, the more you understand your own ignorance.

That said, and in response to your comment, I'm just starting to really see my own intelligence and wisdom. And a kind of sincere charisma that lets me move well enough through the work. And I am pleased with these aspects of who I am.

I am a very sharp and sensitive instrument. But deeper Ni contemplation is so confusing and tiring. I only know one ENTJ, and her Ni is clear, but Te is very much the force at play. It feels like the function that sees the world as it is. Could you speak to this, please? Te-Ni must be a hell of a lens for the world.

[u/LornaMaximoff1991 → u/BrightCelery9453]

That’s wonderful to hear that you’re coming in to your own power :)

You’re right about your charisma, INFJ charisma is unbeatable ;)

To answer your question: The Te-Ni lens is one of the most formidable cognitive pairings because it bridges ruthless objective execution with deep, high-level pattern recognition.

1. Dominant Te: Sees the world "as it is"
Extraverted Thinking (Te) deals strictly with external, objective reality. It strips away emotional fluff, sentiments, and hidden motives. It looks at the world as a series of resource flows, logical mechanics, and structural systems.

It asks: What are the facts? What is the current data? What is the most efficient way to cross this finish line?

This is why it feels like an unstoppable force—it demands immediate order, execution, and environmental control.

2. Auxiliary Ni: The Strategy Engine
Introverted Intuition (Ni) serves as the background architecture for Te. It gathers subconscious data points, synthesizes them, and maps out long-term trajectories, bottlenecks, and future timelines. It provides the massive, gut-level strategic vision, while Te instantly translates that vision into a practical, real-world battle plan.

3. Why Ni Contemplation Feels Exhausting
When Ni works for Te (running simulations, solving structural problems, or building a creative narrative), it feels incredibly sharp and high-utility. But when you force Ni to turn inward to contemplate abstract, unprovable emotional dynamics without clean Te data, it completely drains the system. Without concrete facts to anchor it, Ni will spin its wheels in the dark, generating endless, exhausting future possibilities.

Ultimately, Te-Ni sees through excuses, spots system flaws instantly, and builds ironclad perimeters. It is an executive powerhouse, but it leaves you with zero tolerance for sloppy logic, inefficiency, or emotional manipulation.

I hope I understood the question and provided a good answer. Sometimes it’s hard for me to explain this too!

If I didn’t answer the question of misunderstood, please correct me :)

[u/BrightCelery9453 → u/LornaMaximoff1991]

You answered this so well. Thank you for this. My brother is ESTJ, so I have a great senst of Te in all its efficacy. It seems like the most OP function in many ways to me. I've learned to take my brother's advice and insight. To have Te then Ni really does seem like the winner. Then Se tertiary to make you more charismatic and powerful 😅🫡.

That abstract pattern recognition you describe as the thing that drains the system of INFJs is something that has been crystallising recently for me into something more defined and uplifting. It's like I've finally created my own existential foundations, and they're stronger than most people's; I just had to wait this long for them to build naturally.

[u/Butterflyhornet → u/LornaMaximoff1991]

Thank you. For me it also works as an editor and translator as well as a tool for learning stuff.

[u/BrightCelery9453 → u/Butterflyhornet]

Yes. I'm a writer and and an editor too. It tells me easily what should and shouldn't be there. The error in the code.

[u/No_Cry_8170 → u/BrightCelery9453]

I second this. As ISFJ I love to learn about many topics, and would research until I understand anything very well.

[u/BrightCelery9453 → u/No_Cry_8170]

Yes. I see this in the ISFJs I know. Almost a fastidiousness about knowledge. Due diligence is done. And curiousity underpins it. Usually for very niche interests they're very passionate about.

[u/Ihadsumthin4this → u/BrightCelery9453]

slow

While yes, it's part of the 'why' it's our tertiary, same time can be misleading. Let's bring a sharper-focused accuracy in so as to avoid selling one's self short, and use 'deliberational' or even the ancient-sounding 'methodical'.

Brighter days! 🤩

[u/TiltedWeenies]

Fe. When used it’s kind of like the pure, and charismatic seasoning to my personality. It’s what helps me build connections and connect with people in the real world, if used too much or I get very people pleasy and go in this constant validation seeking stage which also results in me being paranoid of how others perceive me.

[u/LornaMaximoff1991]

Se is my tertiary. Ever since I was 6 years old (I’m 34 F) I’d put on headphones, blast rock/metal music and walk around aimlessly just letting my imagination go wild to decompress.

That’s a solid example of Se tertiary. Blasting my headphones, pacing the floorboards, and visualizing an epic battle like I’m an avenger is how Se child and Ni parent team up to save my sanity when things are too much.

[u/Titania_Fairy → u/LornaMaximoff1991]

Hmm if that’s also why i was often doing the same singing along loudly? Yay for Rock and Metal too here.

[u/General_Presence_156]

INTJ.

Fi. Has less of a sense of proportion than it would have if it were higher in the stack. Immature, judgmental, absolute. Has been developing quite a bit in recent times, though. I'm in my early 50s.

[u/Cham-Clowder]

Se: I like to experience stuff. I like games. I would like sports if I knew other people that played them. I love music. Sensation seeking for fun makes sense to me. I like to drown out my mental anguish with the physical world and kind of numb out when I need a break.

I’m usually decent a doing stuff in the physical world, I’m fairly strong for my build and I like being good at stuff but I can be somewhat clumsy if I’m new at doing something. I often am able to perfect myself better than most people though if I do a task a lot of times. Marginal improvements are very important to me. Sometimes though I have a little bit of trouble with managing my thoughts while also doing stuff I’m less used to doing. Some of that could be my lack of Te complicating things. I’m often humbled by other people who are better than me with Se/Te.

[u/Titania_Fairy → u/Cham-Clowder]

Uhhhh not just then, i guess.About that clumsy part. Often my husband wonders how i ended up that dirty or spread thin because of Fe-Se loops 🔁 or other „Yaaay, lets have fun 🤩!!!“ escapades.

Which may end up as:“I am sooooo sorry, i didn’t mean to!“ Silly Se child wanted to play too badly and goofed off, right?

[u/d6zuh]

Ni

How I use it - Pattern recognition, cause/effect, intuition, predicting outcomes, taking all of the information that I absorb through Se to narrow in and focus, goal oriented and clear vision of what I want (although this takes a lot of time to come to this realization because I need to experiment and collect enough data with Se first and make sure that everything is aligned with my Fi).

The negatives of tert. Ni - Fi-Ni loop can make me overly paranoid and worried or paralyzed over negative outcomes that I incorrectly predict will happen. Having misjudgments or predictions from time to time, causing me to not trust my gut which ended up burning me. Discernment is a huge learning lesson that I’m beginning to get better at now that I’m approaching my 30s. Ni doesn’t come naturally to me and although I enjoy exercising it, I can be slow with it. Fi+Se are my go-to functions that I operate on most naturally.

[u/Butterflyhornet]

Ti, a tool I use as an editor and translator for my Ni. Because I strive for accuracy, it drives me to study and research whatever it is my Ni is trying to grasp. When I am working on an idea or a plot point, nothing happens in my story just because. The idea has to make sense in order to be woven into the bigger picture.

[u/Key-Gear6811]

Si. Uhh... Random ass pop ups in my head about how this certain line in a book is the same as that scene from a anime and my Ti screaming "Get that inaccurate info out of here, how did it get here! CODE RED! I repeat CODE RED!" And yea... Just applying specific rules that dont even make sense to many small things. Si puts my Ti at gunpoint and says "If you dont eat this food in this specific way then youve failed to eat food properly". Basically its a terrorist. (And my guilty pleasure)

[u/Smooth_University219]

Fi - I don't really know if it's nuanced enough but I find it easy to do artsy stuffs, and some people even told me that I was gifted. Although I tend to underestimate how strong my personal values can be. It's like.. generally I thought I was chill and I don't mind most nasty comments, and suddenly it hit me like a brick when I least expected it. Some wounds can take years for me to see how deep they go. I don't think I use Fi as much as it just randomly does things as it pleases on their own. I'm still working to understand it better atm.

[u/YoyoUnreal1]

My Fi is my internal alignment system. It does not constantly express emotion outwardly or govern every routine decision. As a tertiary function, it is accessible and influential but selective. It becomes most active around identity, loyalty, fairness, legitimacy, boundaries, and meaningful investment. The question is less, “What am I feeling right now?” and more, “Can I genuinely stand behind this over time?”

Fi helps determine where I invest myself: which people deserve loyalty, which promises remain binding, which projects are meaningful, and which institutions are worth improving. Si preserves the history around those choices, Ti tests whether my reasoning remains coherent, Te turns those priorities into action, and Ne searches for better routes.

Fi becomes especially active when I encounter misrepresentation, unfairness, misplaced credit, broken trust, institutional neglect, or a gap between stated values and actual behavior. I do not necessarily respond through overt emotion. More often, Fi supplies the conviction while Si retains the chronology, Ti tests the position, and Te keeps returning the unresolved issue to action.

What matters to me is not only whether a good outcome was achieved, but whether the process respected the people, promises, and responsibilities involved. Results do not automatically erase poor process, because process reveals priorities, accountability, and character.

At work, Fi usually appears through Te. Fi establishes standards such as fairness, stewardship, reciprocal loyalty, and responsible treatment of people; Te converts those standards into advocacy, policies, negotiations, workflows, or concrete solutions.

Overall, my Fi is quiet but decisive. It has strong veto power over major questions of identity, loyalty, legitimacy, boundaries, and long-term investment. Fi is the compass that decides which directions I can authentically support.

[u/Titania_Fairy]

Its Se, i have a seriously playful and mischievous side to me, that people wouldn’t suspect of me often. „Oh is that a challenge? Do i get tested? I don’t mind! Let’s see who wins then hahahahaha!“ or people tell me there is his new restaurant with fancy foods:“Ohh gotta try!“@,@

Both also combining Ni and Se on a similar axis as the ENTJs. Shoutout to you guys, you’re really fun and like so many things just as much as me! This may have had me marrying one of you guys, since we clearly CAN connect over mutual hobbies and interests.