ill just add some sources:

Descriptions of the Weak Functions:
Ni – Vulnerable function. LSE painfully experiences any type of uncertainty. It is desirable that everything be planned before-hand, to precisely know what will happen tomorrow, in the week, in the month, in the year. Uncertainty, for her, is the most severe vital problem, it makes her nervous and she attempts to surmount it with all her resources.
LSE is not inclined to give herself up to dreams and fantasies, she finds it difficult to create an internal world that is not connected with reality – her attention is always concentrated on the exterior of things. Therefore she often doesn’t realize the deeper essence of a person or event, but makes judgments based on what she sees (i.e. in regards to whether the man is respectable) and finds her point of view to be sufficiently reasoned.
Her consciousness assumes no mysticism, nothing beyond that which may be seen, touched and checked. Because of the weakness of her introverted intuition she will never compose an intuitive forecast of events, but will prefer to act by means of her strong logical function: thus she will count on things but not foresee them.
Particularly, due to the weakness of intuition, LSE cannot always catch on to the trends of development, prospects for one or another form of production, the possibility of demand for one or another commodity. It is therefore not surprising that she neither hurries to use innovation in the house nor at work nor in administrative activity. May even wear the same suit for years (though nevertheless will wear it properly and aesthetically). In general, in regards to clothing, she is more so guided by worthwhileness (formal fashion), does not so much love “avant garde” styles.
Extroverted intuition is also not among the strong qualities of the LSE: for example, she finds it difficult to correctly evaluate and to sense the nature of other people, their true motives, which push them toward one activity over another. - Filatova


4th Function - Ni Introverted intuition

Representatives of this type frequently say that even if a day had 48 hours, still for them it would not be enough. The volume of work which they aim to carry out often does not fit into the time allotted for it.
One of the problems of LSEs is in the fact that they are poor at factoring in time into their estimates and calculations. Time is their bitter enemy: they want to bring their work to an irreproachable quality, but alas deadlines do not permit for this. They usually compose a daily schedule that is packed with activities, and for this reason, however accurately they try to plan the allotments for each day, they often fall victim to omissions and mistakes when taking time into account.
Establishing norms for activity, the LSE, as a rule, takes neither preparation time, nor reductions in working rate related to fatigue and sickness, nor the time that must be reserved for eating and breaks, nor other kinds of unforeseen time expenditures into consideration. Sometimes there are unpleasant incidents when the LSE pesters his subordinates with questions of the type: "How long is it possible to talk on the phone?!" or "How long do you plan to take your smoking break?" When matter concerns expenditures of working time, the LSE is capable of exceptional unceremoniousness - up to hinting that someone is taking too much time in the bathroom.
An impression is created that the LSE experiences disappointment every time others take a break, stop their activities, finish their study or work day, ask for a sick leave, or use their annually allotted vacation time. (LSEs let their workers take vacations extremely unwillingly.)
In the understanding of the LSE, a careless approach to one's productive time is the most terrible misdeed. If some deficiencies in professionalism and technical errors he is somehow willing to suffer, then squandering of working time of oneself or others (which is even worse) or creation of more working hours - is the most terrible crime in his eyes.
Low productivity is sufficient reason for getting fired.
LSE attributes many of his failures to his weak ability to manage timeliness of his activities. Missing time is very unpleasant for him. He estimates how much work there remains to be done and is often dissatisfied by results of these assessments.
Time is the most valuable and sacred of all his resources. LSE will never allow himself to misuse some else's time. A person who is inconsiderate with other people's time he perceives as a great social evil. (LSE, for example, feels indignant over the fact that someone has scheduled two business meetings for the same time but in different places. If this occurred due to someone's forgetfulness or the absent-mindedness - this is still unforgivable.)
Lateness he perceives in the same manner as getting shortchanged or under-weighted at a produce market. Lateness is stolen time (nothing more nor less than that). Himself tries to be exceptionally punctual, at least in the initial stages of relations.
As has already been mentioned, any unforeseen expenditure of the time is unpleasant for LSE. The need to complete work in short time frames drives him into panic. Then, he tries to start on work in advance ("She started working on her graduation project earlier than everyone else in class. Even before the requirements for project were announced, she was already done with it, though later she had to re-do several parts.")
Expenditures of time for LSE are first of all examined from point of view of their expediency and reasonableness. Time spent on studies, work, personal affairs, in his understanding is spent well.
He hates wasting time for nothing and does not associate with those, who misuse and waste other people's time.
Even in presence of interest in public life and political events, for LSE it is difficult to "keep up with the times". He is conservative in the depth of his soul, and does not always acknowledge and accept the concurrent innovations and novelties.
In this, LSE is complemented by a partner who is capable of not only seeing global changes with time, but also to convince him to take them into consideration, which is skillfully done by his dual, the EII. Punctual, responsible, gentle and unobtrusive in the contact, he constantly reminds the LSE about the most pressing matters, keeps track of his time expenditures and suggests how to set them to an optimum. He watches over his daily schedule and makes sure that his partner is not overloaded by work.
(LSE himself, however thoroughly he plans his day, always overloads it with activities, even if this is a day for rest. Even worse, when LSE compiles a program for daily activities for someone else: one of the representatives of this type, receiving his relative at his house (LII) organized her "leisure" time in such a manner, that in a couple of days she had a nervous breakdown, which incited a family quarrel and a break in their relations.)
EII adjusts the schedules and programs of LSE by forcing him to take into account people's physical capabilities, asking him to pay more attention to his health, and to set time aside for rest. - Strat


4th Function - Ni Introverted intuition

Under the influence of his moods and states, some unforeseen matters constantly appear before the ESFj, some kind of desire to do something that was not in his plans. Becoming fascinated and absorbed into some matter, the ESFj frequently ignores the time factor - it is as if he wants to stop time, or to think that it has stopped, although the ESE knows very well that this isn't so and worries much in this respect. The ESFj constantly feels a wish to do more than he can in the available time, and, as a consequence of this, there is a constant fear of getting overloaded, stress, fussiness, nervousness, and a sensation of being exhausted.
The ESFj finds it very difficult to plan out his day. His schedule of activities often gets either altered and shifted or filled to a greater density.
The ESFj fears any unforeseen expenditures of time. Any unnecessary over-expenditures of time greatly annoy him. The ESE feels irritated by an uninvited guest, by an unexpected telephone call, by an unwelcome visitor. He feels irritated by the need to re-do his work, which means spending extra time on it. He is irritated by the need to wait for public transport for too long, by excessive traffic on the roads, by the need to stand and wait in a line in stores. (One cannot envy the person who attempts to get ahead in line right before ESE's eyes.)
The ESFj constantly hurries himself and constantly rushes others. Frequently, when the ESE is in an unbalanced, overexcited state, some feverish impatience with the notes of irritation in the voice can be seen with him.
It can be unpleasant to witness how the ESFj upon arriving for a guest visit is already hurrying to go somewhere else. This greatly interferes with communication with him - he as if rushes and hurries up whoever he came to visit: being in a hurry, the ESE inquires about all the latest news, quickly examines the interior and any new acquisitions, creates a fuss around meal preparation, and then starts looking at the clock - it's time to go home!
In people the ESFj is annoyed by slowness, sluggishness, awkwardness, insufficiently fast responses, and insufficiently rapid mental acuity.
The ESFj also feels irritated when the conversation returns to the topic which he considers to be exhausted for himself.
The ESFj gets irritated when "the empty is poured into the emptier". That is, he feels irritated by insufficient informativeness of a conversation - in such cases he is overcome by a sense of an empty waste of time.
The ESFj rarely succeeds in finding a time to read. Thus, representatives of this type often do their reading in public transport, while traveling, waiting in lines, late at night before going to sleep, or early in the morning before getting up. They also dislike books that feature slow development of topic or events or that are too detailed in their accounts.
The ESFj dreams about that time when he will be able to live without hurrying and manage to do everything that he wants. But this desire remains as an unfulfilled and unrealizable dream. The ESE cannot always allow himself to quietly sit with some craft or needelwork - he gets constantly tormented by a sense of irrationally utilized time. Therefore, representatives of this type try to combine all matters that can be done simultaneously: if the ESE is sitting and sewing, then simultaneously there is something washing in the laundry, cooking in the kitchen, he's watching something on television, and, on top of that, he also manages to answer the phone.
Constantly living in a regime of heightened activity, the ESFj does not manage (and does not allow himself) "to make a pause", to stop and analyze the situation, to see its overall development in time, and to correct his plans for the future as might be needed.
The ESFj cannot rationally and economically expend his forces. For him it is very painful to hear criticisms about untimeliness and inopportuneness of his actions.
The ESFj finds it unbearable to endure accusations of unproductive expenditures of time. He feels irritated when he is being limited in time: he already tries to spend it maximally rationally, but if this is not achieved it's because the ESE, as any sensing type, takes onto himself additional responsibilities. Therefore, some unforeseen pressing matters constantly appear before him.
The ESFj greatly dislikes being late. He tries to conceal his incapacity to accurately calculate and estimate time: for example, running way too late for some event or social gathering, he will suggest to not go at all. Suffers when he is criticized for insufficient punctuality.
The ESFj always feels nervous when he has to coordinate his activities or events in time: for him it's very difficult to feel the flow of time, therefore he has great difficulty with estimating the timeliness and time duration of any events, work, or activities. (Any type of work connected to coordination of time is best avoided for representatives of this type.)
The ESFj without fail tries to be up to date in all news and all events, since, as has already been mentioned, he is distinguished by an active civic stance. He is always interested in potentially upcoming social and political changes and prospects, and the newly appearing possibilities that they bring. The ESFj constantly hopes for changes that will open up new prospects for himself. He counts on resolving his personal problems with their help.
The ESFj - is an optimist, and waits for only the best from life. For this reason, unforeseen complications and troubles greatly dismay him. (The ESE is even dismayed by movies and books with a sudden bad ending.) The ESE doesn't like skeptics who foretell of complications and problems, and extinguish initiatives. Even if the ESE himself feels upcoming troubles, he prefers not to seek advice from those who see the future only in dark color.
The ESFj greatly tries to be farsighted and prudent, which unfortunately he does not always accomplish. Therefore, he painfully reacts to any criticism in this regard.
This position radically changes when his dual becomes his partner. The INTj knows how to plan out time magnificently well and such that there would be no causes left for overloads, hurry, and stress. The LII corrects ESE's plans, regulated the rate of his activity, creating a regime that is optimal for his vitality and health - conditions that combine high output of work and rational use of time.
In terms of making forecasts, the INTj is also more preferable for ESFj than other intuitive types, since it is only people of this type who are subconsiously oriented at the intuitive sensations of ESFjs. Furthermore, LII's forecasts always have some kind of logical substantiation, and therefore they seem especially convincing for the ESE, since the ESE gets convinced only by that which is logical.
With the aid of INTj, the ESFj is able to rationally use and save time, which is necessary for consideration and solution of important problems, since any thought, which the ESFj has unsuccessfully attempted to consider, to base and to understand, in the account of INTj immediately becomes simple, natural, and accessible for his understanding. - Strat


Descriptions of the Weak Functions:
Ni – Vulnerable function. This is the weakest function. ESE poorly estimates the timeliness of actions and events. She finds it difficult to distribute energy so as to have time to do everything. Prefers to act immediately as the needs arise, and is usually a very active person.
She evaluates people by how they relate to her and can therefore mistake others and their motives. She is trusting and easy to deceive.
Finds it difficult to penetrate into the deeper, concealed possibilities of events. She reasons poorly in such cases. Therefore in some situations she’ll accept what is deemed appropriate and approved by others while in other situations her temperamental, courageous nature may push her into risky activities.
Due to a weakly developed intuition ESE frequently seems conservative. She poorly visualizes the aftereffects of various activities and thus prefers concrete knowledge concerned with the short-term. - Filatova