You are the Universe~ Psychology and Spirituality

MBTI Cognitive Functions

*all due credit to artsymbti on tumblr, none of this is mine, but i found it to be extremely helpful and concise.*

So if you've been wandering around what I call the "MBTI fandom," you've probably seen numerous posts talking about something called cognitive functions. And you're like, "learning the order of the letters is hard enough, and now there's SUBCATEGORIES!?!?"
Yes.
And this is where the real magic of this thing called "Myers-Briggs" comes into play. Sure, the descriptions you read on 16personalities.com were great, but what really makes your type accurate is what's behind those 4 little letters. Which is...four more letters.
Here is a list of all of the cognitive functions–and don't be too daunted by them!! You'll understand them with time.

ESTP: Se > Ti > Fe > Ni
ISTP: Ti > Se > Ni > Fe
ESFP: Se > Fi > Te > Ni
ISFP: Fi > Se > Ni > Te
ENTP: Ne > Ti > Fe > Si
INTP: Ti > Ne > Si > Fe
ENFP: Ne > Fi > Te > Se
INFP: Fi > Ne > Si > Te
ESFJ: Fe > Si > Ne > Ti
ISFJ: Si > Fe > Ti > Ne
ESTJ: Te > Si > Ne > Fi
ISTJ: Si > Te > Fi > Ne
ENFJ: Fe > Ni > Se > Ti
INFJ: Ni > Fe > Ti > Se
ENTJ: Te > Ni > Se > Fi
INTJ: Ni > Te > Fi > Se
And there you have it. Find your type in there and see what it looks like. I'll explain each one of your functions down below. But what you need to do is follow this order: Dominant > Auxiliary > Tertiary > Inferior
And what that means is first > second > third > fourth. For example, if you're an INFP (Fi > Ne > Si > Te), the dominant function is Fi, the auxiliary function is Ne, and so on.
Read about your functions in their proper order to understand what they mean for you.

Extroverted Sensing (Se)
Dominant Se: ESFP, ESTP
Dominant Se is the function that is associated with appreciating sensory things to the fullest without restraint. A dominant Se user will engage fully with their environment to fullest extent without restraint.
Dominant Se Monologue:
"I want to sample all of the experiences that are immediately available to me and see where those experiences lead me!"
Auxiliary Se: ISFP, ISTP
Auxiliary Se is the function that leads its user to engage with the sensory aspects of their environment that they have deemed most enjoyable, important, or useful.
Auxiliary Se Monologue:
"I want to go live out the experiences that I have determined to be the best or most enjoyable and see what happens as a result."
Tertiary Se: ENFJ, ENTJ
Tertiary Se is the function that allows its user to pick up on cues from their environment and react to them with a natural sort of ease and confidence.
Tertiary Se Monologue:
"I prefer to plan ahead, but when necessary, I can think surprisingly well on my feet, as I feel in tune with what is going on around me."
Inferior Se: INFJ, INTJ
Inferior Se is the function that manifests, in a person's earlier years, in such a way to make the user distrust their environment or belief that sensory aspects of life are superficial or even stupid as compared to that of intellectual aspects of life.
Inferior Se Monologue:
"I must analyze all possible outcomes of a sensory experience, as the physical world is subject to change unexpectedly, at any time."
As the user of inferior Se matures, this last function will become increasingly stronger and lead the user to trust their environment and senses with time, and even value them.
Introverted Sensing (Si)
Dominant Si: ISFJ, ISTJ
Dominant Si is the function that makes its user structured, grounded, consistent, and allows the user to possess a fantastic memory. A dominant Si user will want to act in such a way as to maximize their efficiency and actions according to what has worked in the past.
Dominant Si Monologue:
"I prefer to plan the majority of my life around the traditional or tried-and-true methods of doing things, as they have proven to be the most reliable."
Auxiliary Si: ESFJ, ESTJ
Auxiliary Si is the function that leads its user in the direction of organizing and structuring their environment in a "tried and true" way.
Auxiliary Si Monologue:
"In order to achieve what I want, I will employ the most reliable and socially acceptable method of accomplishing it."
Tertiary Si: INFP, INTP
Tertiary Si is the function that grants its user the ability to recall what has been important to them; a strong memory (i.e. recurring nostalgia) as well as a mild reluctance to significantly change their environment.
Tertiary Si Monologue:
"I will examine how my new experience or theory sizes up against my past experiences or way of understanding the world."
Inferior Si: ENFP, ENTP
Inferior Si is the function that manifests, in a person's earlier years, in such a way as to lead its user to resist structure, "stifling control," and even rules (societal or otherwise).
Inferior Si Monologue:
"These rules are stupid! They're just limiting my ability to live up to my potential. I want to do what I want, when I want. I need FREEDOM!"
As the inferior Si user matures, however, they will begin to understand the importance of structure to the world and even use traditional methods of accomplishing things for themselves..
Extroverted Intuition (Ne)
Dominant Ne: ENFP, ENTP
Dominant Ne is the function that I like to call "the filter." It's the dominant function for all ENPs. And since ENPs have a second, more structured function (Fi or Ti), Ne manifests in making that second function "out of the box," or a bit "crazy." It leads its user to focus on concepts, theories, and what could be. Dominant Ne users are very future-oriented and believe strongly in self-improvement.
Dominant Ne Monologue:
"I am swimming in an endless sea of possibilities about what to do/experience/think about next and I want to try them all at some point."
Auxiliary Ne: INFP, INTP
Auxiliary Ne leads its user to think up a multitude of ideas after considering a feeling or thought for awhile. May lead the user to be seen by the public as "quirky" or "odd," and may also manifest as humor.
Auxiliary Ne Monologue:
"I see a million different ways to look at the concept I've been analyzing and I want to consider them all."
Tertiary Ne: ESFJ, ESTJ
Tertiary Ne is the function that leads its user to come up with a series of inventive and creative ideas that support their progression towards a goal.
Tertiary Ne Monologue:
"I will consider which possibilities will best help me accomplish the goal I have set."
Inferior Ne: ISFJ, ISTJ
Inferior Ne manifests, in a person's earlier years, in such a way as to make the user doubt or resists any sort of "newness" in their environment. Anxiety towards change is a common manifestation of this function.
Inferior Ne Monologue:
"It is best to stick to the most reliable methods of getting things done. There is no sense getting lost in a sea of unpredictable possibilities."
As the inferior Ne user matures, however, they will begin to understand the importance of change and theory and the uncertainty of new possibilities.
Introverted Intuition (Ni)
Dominant Ni: INFJ, INTJ
Dominant Ni is what makes its user perceptive to patterns and underlying information in the user's everyday life. Symbols and concepts are typically of much importance to the dominant Ni user.
Dominant Ni monologue:
"Everything is interconnected and I must determine the meaning and implication behind those connections."
Auxiliary Ni: ENFJ, ENTJ
Auxiliary Fe manifests as a keen perception of how the user will go about achieving their goals. The user intuitively knows the steps they will have to take in order to reach point B from point A.
Auxiliary Ni monologue:
"How can I use my intuitive knowledge about how things are connected in order to achieve what I want?"
Tertiary Ni: ISFP, ISTP
Tertiary Ni manifests as a desire to perfect one's pre-existing skills and "connect the dots" between thoughts and emotions.
Tertiary Ni monologue:
"How can I improve upon – or even perfect – the approach that I regularly take toward my main passion or interest?"
Inferior Ni: ESFP, ESTP
Inferior Ni, in a person's earlier years, will manifest as a sort of underlying anxiety or doubt that there is more to the problem than what is at face-value. It may surface as a distaste for planning for the future and over-analyzing.
Inferior Ni monologue:
"Everyone needs to stop over-analyzing everything, the answers are literally right in front of us."
As the individual matures, this function will develop so that the user will feel comfortable "reading between the lines" and discovering that there is usually more to a problem at hand than what is at first glance.
Extroverted Feeling (Fe)
Dominant Fe: ENFJ, ESFJ
Dominant Fe is what makes its user kind, humanitarian, and aware of social systems. Dominant Fe users look to other people in order to decide their course of action and are strongly influenced by those around them, usually in that they want to keep peace.
Dominant Fe Monologue:
"I will make those around me feel comfortable and happy in a cohesive manner, by identifying what we are all mutually striving for."
Auxiliary Fe: INFJ, ISFJ
Auxiliary Fe is the function that makes its user sensitive to the people around them. It leads the user to make decisions based upon what will be best for everyone.
Auxiliary Fe Monologue:
"I will analyze the information that is available to me and then see how I can use it to achieve interpersonal peace."
Tertiary Fe: ENTP, ESTP
Tertiary Fe is the function that leads its user to become aware of others' emotions and motivations. Tertiary Fe users are conscious of social systems and use this understanding to their personal advantage, whether it be social acceptance, love, appreciation, fear, etc.
Tertiary Fe Monologue:
"I will use what I understand about the people's feelings around me to get what I want."
Inferior Fe: INTP, ISTP
Inferior Fe manifests, in a person's earlier years, in such a way as to make the user doubt their ability to understand their own emotions and others' emotions. Emotions will seem like "the enemy" as compared to the user's normal calm logical thought processes.
Inferior Fe monologue: "Feelings make me freeze with anxiety because I don't know how to moderate them. I am terrified of accidentally offending someone."
As the user gets older, however, their ability to use Fe and understand it will improve, and the user will be more confident with emotions and understanding their own and others'.
Introverted Feeling (Fi)
Dominant Fi: INFP, ISFP
Dominant Fi is what makes its user possess a strong moral compass based on values that have been established upon past experiences and thoughts that can be used to judge future events.
Dominant Fi monologue:
"I must decide how I feel and where I stand on these issues before coming to a conclusion about what to do."
Auxiliary Fi: ENFP, ESFP
Auxiliary Fi manifests in such a way as to make its user take a step back to consider where they stand on a certain issue based on past experiences.
Auxiliary Fi monologue:
"I need to isolate myself to process how I feel about the activities I've been engaging in lately and decide whether or not to keep doing them."
Tertiary Fi: INTJ, ISTJ
Tertiary Fi manifests in that it makes the user unwavering upon certain held beliefs and principles. The user utilizes tertiary Fi to make important decisions and process specific information.
Tertiary Fi monologue:
"I must adhere to my values and morals at all costs – even if doing so is unpleasant."
Inferior Fi: ENTJ, ESTJ
Inferior Fi, in a person's younger years, may manifest in such a way as to make the person uncomfortable or disapproving of expressing emotion, as emotion is seen as a weakness.
Inferior Fi monologue:
"Feelings are for the weak. I have no time to attend to such trivial matters in either myself or others."
As the individual matures, emotional maturity increases and will grant its user the ability to consult their feelings on important issues and see their usefulness in everyday life–without fearing them or seeing them as a hindrance to their plans.
Extroverted Thinking (Te)
Dominant Te: ENTJ, ESTJ
Dominant Te is what makes its user outright, confident, and unwavering when it comes to their goals. The user can clearly see the path that is to be taken in order to reach a certain goal.
Dominant Te monologue:
"I will achieve my goal by any means necessary."
Auxiliary Te: INTJ, ISTJ
Auxiliary Te is what makes its user certain of what is to be done based on a past experience or thought/premonition. They see the concrete path before them that will allow them to accomplish their goal.
Auxiliary Te monologue:
"Now that I have determined the best or most reliable course of action, I will set it into motion using the most straightforward method available to me."
Tertiary Te: ENFP, ESFP
Tertiary Te manifests in that the user will have an underlying sense of what must be done to reach a goal using the resources around them.
Tertiary Te monologue:
"I will employ the most straightforward method that exists in order to make my goal, dream or impulse come true."
Inferior Te: INFP, ISFP
Inferior Te, in a person's younger years, will make the user doubt the path ahead of them in order to reach a certain goal. They may fear having to set a plan into motion in order to achieve desired results.
Inferior Te monologue:
"I have many goals I want to accomplish but often have trouble tangibly setting them into motion. I fear being perceived as incompetent by others."
As the individual matures, they will improve in their understanding of how to set plans and actions forward in order to get what they want and need to thrive. Fear of incompetence subsides, and logic becomes a powerful tool that can be used to convince others of the correctness of their plan.
Introverted Thinking (Ti)
Dominant Ti: INTP, ISTP
Dominant Ti is what makes its user thoughtful, careful with details, and keen of logical patterns.
Dominant Ti monologue:
"I must figure out exactly how everything logistically works in relation to everything else."
Auxiliary Ti: ENTP, ESTP
Auxiliary Ti is what makes its user depend on logical systems to sort out their outer observations. This function can be used to discern what can be used to their advantage out of a plethora of information.
Auxiliary Ti monologue:
"How can I manipulate the way that this object or situation works so that it instead works the way I'd like it to?"
Tertiary Ti: INFJ, ISFJ
Tertiary Ti manifests in such a way as to make its user thoughtful in that the user sorts through prior information and feelings in a logical manner.
Tertiary Ti monologue:
"Where does this new hunch or piece of information I've acquired fit in relation to what I already know to be true?"
Inferior Ti: ENFJ, ESFJ
Inferior Ti, in the user's younger years, will manifest in such a way as to make the individual critical of others as they attempt to definitively "peg" a person's personality or mannerisms.
Inferior Ti monologue:
"Can I use these objective observations about others to my advantage?"
As the user develops, however, so will the inferior thinking function, which will eventually allow the individual to pick up on key information in a positive, meaningful way, and will be able to use these gathered tidbits of information to guide and nurture others.