What is 'explain like I'm five'?



In my recent question, I got this link in an answer.

Here, 'Explain like I'm five' is written. I tried to find its meaning on the Internet, but I got only an acronym ELI5.

Is 'explain like I'm five' a phrase or an idiom? What does it mean?

Rucheer M

Posted 2016-01-20T05:26:51.873

Reputation: 4 555

From the mentioned link: "It is only plural when referring to objects you can count discretely (eg. zero matchsticks). Zero does not pluralize a noun which can't be quantified (eg. zero tolerance, zero effort). Grammatically, zero is synonymous to not any, and since any refers to an arbitrary number of countable objects, we pluralize the noun it goes with (eg. I do not have any apples)." <-- not for a 5yo (I think); "It just is." <-- for a 5yo (but perhaps not very enlightening. :-) – Damkerng T. – 2016-01-20T09:56:12.480

17First of all, you should know that English sentences like "I am five", "she is 38", etc., are understood to refer to the person's age, in years. (But do not mix this up with sentences like "I am fifty dollars in debt".) – Nate Eldredge – 2016-01-20T16:27:04.253

4@NateEldredge I was once talking (in English) to a native French speaker, and it was a bit confusing when she said, about something that had happened with herself and a group of friends the day before, "we were thirteen," because she was in her 20s. After a bit of clarification I realized what she meant was "there were thirteen of us [in the group]." – Mason Wheeler – 2016-01-20T16:30:37.637

Its use may come from a well known sentence by Groucho Marx: A child of five would understand this. Send someone to fetch a child of five. (ex: http://www.brainyquote.com/quotes/quotes/g/grouchomar100440.html )

– Olivier Dulac – 2016-01-20T17:07:02.033

Philadelphia?? The movie, with Tom Hanks and Denzel Washington?

– Mari-Lou A – 2016-01-20T19:48:22.530

3This reminds me of inception. You want us to "explain like I'm five" like your five. – n00b – 2016-01-20T22:00:10.220


If you can find this episode of the US version of the TV show The Office (or watch this youtube video), this phrase is used. The boss can't understand the concept of a 'surplus', and needs it explained as if he were 8 years old. When that doesn't work, he asks for the description you would use for a 5 year old.

– pjs36 – 2016-01-21T04:27:06.353

"If you can't explain it simply, you don't understand it well enough." Albert Einstein – Fabian Blechschmidt – 2016-01-21T16:09:09.010

1The reddit site describes it well: 'E' is for explain. This is for concepts you'd like to understand better; not for simple one word answers, walkthroughs, or personal problems. 'LI5' means friendly, simplified and layman-accessible explanations. Not responses aimed at literal five year olds (which can be patronizing)." So explain it in a simply, friendly manner, using commonly understood terminology, but not as though you are literally addressing a 5 year-old (unless the person is actually 5). – user70848 – 2016-01-21T16:52:56.900



It's a shortened form of

Explain like I'm five years old.

I'm not sure whether this already has the status of an idiom, but it's quite frequently used.

The meaning is quite literal:
Explain a complicated subject in a way a five year old can understand.


Posted 2016-01-20T05:26:51.873

Reputation: 14 048


To add a little context: many people believe that, if you can explain something so that a 5-year-old child can understand it, that is the ultimate test of how well you understand something (example). Also, asking an expert to explain something as if they were talking to a child is a good way to stop them from using jargon or making assumptions about what you "should" already know.

– user56reinstatemonica8 – 2016-01-20T11:43:43.220

12@user568458 +1 for "stop them from using jargon or making assumptions about what you 'should' already know". These are big problems I face in my (IT) job. Often people try to use jargon to sound "smarter" but _mis_use it, and cause communications problems. Others describe things with acronyms and nicknames that may make perfect sense to them, but mean nothing to me. So while I don't literally ask for the 5-year-old version, I do often ask people to explain the terminology they're (ab)using. – Monty Harder – 2016-01-20T17:51:43.583


I'm not sure where the phrase originated, but I think the online Reddit community has definitely made it more popular.

– Alex W – 2016-01-22T20:04:20.177


The phrase means 'explain it to me in very simple terms, as if I were only five years old'.

Whilst someone using this might mean that they really don't understand, it is also possible that the person asking suspects that the person explaining doesn't really understand either and is only parroting jargon.

No'am Newman

Posted 2016-01-20T05:26:51.873

Reputation: 964

2+1 for "[suspecting] that the person explaining doesn't really understand" – DSKekaha – 2016-01-20T15:08:26.630

2Another +1. I've learned to detect people trying to cover lack of understanding with jargon. I find that a few clarifying questions can confirm my suspicions in short order. – Monty Harder – 2016-01-20T17:58:35.347

@MontyHarder relevant xkcd comic

– Spehro Pefhany – 2016-01-22T19:57:03.073

I've always been told that "If you can't explain it to a ten-year-old then you don't understand it yourself". – PCARR – 2016-01-24T14:07:40.407


It means, "Please explain it to me in the simplest possible terms, as one might explain it to a five-year-old child." I sometimes say that to someone who is explaining technical matters of computing to me, for instance, where I am reasonably computer-literate but know little or nothing about programming or the inner workings of my laptop. Does this make sense? It's not an insult, it's just a request for a patient, easy to understand explanation.

Mark Hubbard

Posted 2016-01-20T05:26:51.873

Reputation: 4 298


To fully answer this question, one must first examine the underlying assumptions of the statement "Explain like I'm five", mainly, what does it mean to "Explain" and what is the relevance of being "five". Let us first elucidate the bourn of this directive. For the sake of clarity, we should begin by prescribing to the aesthetic justification of Occam’s razor. As Thomas Aquinas stated, "If a thing can be done adequately by means of one, it is superfluous to do it by means of several; for we observe that nature does not employ two instruments [if] one suffices." With this in mind, it is most likely that an unobfuscated exegesis is being solicited from the requester.

In Stephen R. Shirk’s book, “Cognitive Development and Child Psychotherapy”, he states that “By recognizing the implications of the self-definition in a social and psychological context, the 15-year-old’s response can be said to be developmentally advanced relative to that of the 5-year-old.” One can only assume that the intersection of the definitional self and the subjective self is the key factor in having chosen “five” as the conditional context for the desired exposition.

The B

Posted 2016-01-20T05:26:51.873

Reputation: 67

10Too complicated, didn't read. Please explain it like I'm five! – Josef says Reinstate Monica – 2016-01-20T10:22:50.643

2@Josef A typical five-year-old kid is stupid (or, rather, uneducated) enough to get confused by long complicated words they don't understand, and smart enough to understand a long explanation that doesn't have complicated words in it. That's basically what The B is saying, except wrapped up in a lot of philosophy. (Even I'm not smart enough to understand philosophy.) – January First-of-May – 2016-01-20T14:37:49.813

4For those who didn't get it, The B appears to have just done performance art, by deliberately constructing precisely the sort of obfuscated presentation that elicits "Explain like I'm five", which Josef dutifully provided. +1 for the brilliant demonstration, both of you. – Monty Harder – 2016-01-20T19:08:58.277


Thanks @MontyHarder . I was also trying to provide an example to this question simultaneously.

– The B – 2016-01-21T10:22:35.697

What is this I can't even- – Zenadix – 2016-01-21T16:08:27.440

@MontyHarder - I got it, incidentally. Just wanted to give the explanation anyway. – January First-of-May – 2016-01-25T14:15:27.653


"Explain like i'm five" simply means that the explanation should be elaborate at the same time very easy to understand. The situation should be explained in its most elementary form, as one would explain something to a five year old child. The explanation should be detailed and should be elaborate enough, yet explained in its simplest form.

Varun Nair

Posted 2016-01-20T05:26:51.873

Reputation: 7 920


This phrase is used primarily in the academic and professional world, and typically in one of three scenarios.

In one situation, the person requesting the explanation does not fully understand the concept or situation being discussed, and is requesting a basic explanation that uses simpler terms. The explanation will probably include a number of oversimplified analogies. In this scenario the person asking might not have a personal relation at all to the subject matter; however, academics and professionals from nearly related fields may use this phrase to indicate some interest in their colleagues' work. Here, it would mean something like, "I'm not sure I understand, but I am interested - please explain this idea to me."

In another situation, two persons may be having a professional discussion in which a superior is asking a subordinate (or potential candidate) for a brief demonstration of real understanding. This typically takes the form of a question posed during a job interview, but is also occasionally used during other certification interviews. In this context, it means something more like "Please demonstrate for me that you understand the most essential elements of the subject."

The final scenario is also typically between two working professionals, but is spoken more abruptly, in a manner that indicates frustration or impatience. In this situation the meaning becomes "I am very busy, but I need to fully understand what you're trying to explain. Slow down, and give me the most important parts." This usage would typically follow some kind of inter-disciplinary interaction concerning a growing problem. One might imagine an accountant explaining his changing needs to a software engineer.

Sean Boddy

Posted 2016-01-20T05:26:51.873

Reputation: 119


Let me explain this to you, like you were only five years old...

... it means, making a complicated matter easy to understand. Like you would do for a little child with limited understanding.


Posted 2016-01-20T05:26:51.873

Reputation: 111


It simply requests to explain the thing in very simple words, as if the person to whom it is being explained is just five years old.

Shiven Sinha

Posted 2016-01-20T05:26:51.873

Reputation: 111