How Many Fs Do You See

How many Fs do you see?

There is a neat puzzle that has been doing the rounds for a while now, which asks a very simple question, namely how many Fs do you see in the following sentence?

how many fs do you see - business english success

“Finished files are the result of years of scientific study combined with the experience of years.”

Give it a go now and take note of your count. Don’t over-think it and don’t spend a lot of time on it.

Did you get an answer? Your answer is correct.

What?!? How can this be? Well, the question was “How many Fs do you see?” If you only saw two, then that is the correct answer.

Admittedly, that was a bit cheesy and pedantic, so let’s modify the question and make it a bit more robust by asking

How many Fs are there in the following sentence?

You probably answered three, yes? This is the answer most people give. Or more accurately, this is the answer most native speakers give.

The answer

There are actually six instances of the letter ‘f’ in that sentence – go back and check.

If you still only see three, then check out the three times the word ‘of’ appears, they have the letter ‘f’ as well. Maybe this representation is more helpful.

Finished files are the result of years of scientific study combined with the experience of years.”

Infuriating, isn’t it?

The standard (incorrect) assessment

Most of the places where you see this riddle then draw the simple conclusion that the more you see, the more intelligent you are. Wasn’t that a fun pattern-matching exercise.

This conclusion greatly misses the point of the exercise and, as we will see, has nothing to do with intelligence, but more to do with how we process language.

The linguistic assessment

There are two factors that will influence your answer.

Firstly, the question itself (how many fs do you see) was a little bit mean, as it misdirects you into thinking that a letter ‘f’ has a hard sound, like ‘fail’, but not a soft sound like ‘of’ (where is sounds more like a ‘v’).

The first two words in the sentence (finished files) reinforce this incorrect subconscious thinking.

When we read the test sentence, because the word ‘of’ doesn’t sound like it has an ‘f’ in it, we don’t count it.

The other point is that when we process language, we don’t give the same importance to every word. We tend to skip the little words, such as ‘in’, ‘on’, ‘of’, ‘at’ etc. and give most of our attention to the nouns and verbs. In other words, when we read the test sentence, we don’t really read the three instances of the word ‘of’ – we just blur past them.

These two points account for why native speakers tend to see three, instead of six.

Native speakers?

I’ve specifically mentioned native speakers more than once and there is a reason for this.

When you first learn a new language, all of the words are unfamiliar and all have equal importance. As you get more familiar with the language, you start to process the words in a more targeted way, for example, glossing over the small, familiar, words.

What this means is that if you give this test to someone who doesn’t speak English, they will most likely get the correct answer of six because, for them, it really is a pattern-matching exercise.

The astonishing conclusion is that the better you are at English, the more likely you are to get the wrong answer. This is not how tests are supposed to work.


This has implications for proofreading. When I’m proofreading my own text, I admit to having a blind spot. I know what the text is supposed to say and my brain does a great job of auto-correcting. I see what is supposed to be there, instead of what really is there. For other text, once I’ve read it a couple of times, the same effect occurs (to a lesser extent).

This is one of the reasons I like Grammarly. It reads your text for the first time, every time, and has no idea of your intent.

I hope you enjoyed this post.

Did you get the right answer? Do you have an alternative explanation?

I’d love to hear your comments.

16 thoughts on “How Many Fs Do You See”

  1. I used to use this exercise as part of a session on disability awareness. The point of ‘not seeing’ was what I wanted participants to think about. If we miss something as simple as this, what else are we missing in our daily lives as a result of us ‘skimming’ and making assumptions.

  2. Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn’t mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.

  3. I’ve always liked this riddle. The first time I ran across it was when the company I had been working for was bought out and we were meeting the new management team. They had our entire shift in the meeting room and put this on the board at the front. They went through and asked us to raise our hands and lower them when they said the number we counted.

    By the time they got to 6, I was the only one with my hand up. I kept thinking it had to be some kind of joke when my coworkers started dropping their hands! Then I had to come up front and point each one out.

    They never did explain the point of this exercise to us. Thank you for shedding some light on it for me!

  4. Haha, not fair. Yes, I counted 3. This is great and it comes at a perfect time. I am really focusing on improving my Spanish because I plan to retire from the military in the next 3 years and I want to travel South America teaching English. This seems like a great resource to help me in both fronts, thanks for the information!

  5. English has always been my favorite school subject, so I am in love with this blog, haha!

    A similar version of this riddle was first shown to me and my classmates during fifth grade English class (many years ago, haha) as the only question on our proof reading test.

    Although all of my classmates wrote their answer and handed in their test at the front of the class almost immediately, I was suspicious. I also had developed a strong affection for writing and proof reading. I sat at my desk, reading the sentence over, and over, and over before feeling confident that my initial answer was correct: three.

    During the twelfth time reading the sentence, I also spelled every single word “out loud” in my head; that’s what caused the light bulb to turn on. There were six Fs, not three!

    I was the only one in my class to pass that test. When I saw the teacher five years later as a sophomore in high school, she said she still used that exam for proofreading in her fifth grade English class, and there had only been one other student after me to pass it. How crazy is that?!

    I really like that you broke down the assessment of the riddle and explained the real reason why people so often miss the other three Fs. I appreciate even more that you clarify intelligence has nothing to do with it! It seems as though an individual’s level of attention to detail and the time taken to review the sentence are the main two contributing factors whether the right answer will be given.

    Great post! I will definitely be stopping in often to fulfill my English-nerd desires and improve my writing ability!

    1. Hi Liz,
      Thanks for your great story. During my maths courses at uni, I also developed a strong mistrust of the word ‘interesting’, as in “you’ll like the homework, it’s interesting”. It usually meant that is was either really hard, or it looked really easy but had a huge gotcha! in there.
      Looks like you were right to have a closer look 🙂

  6. Great riddle. Of course I got the wrong answer even though I skimmed the words and counted the Fs.
    Great example of intent and what you are asking as oppose to what people interpret.

  7. This is amazing. I initially spotted 3 ‘f’s and then I noticed the ‘of’s and got it correct. I think it’s quite clear that I’m not a native English speaker. But that doesn’t mean I’m good at proofreading either. I still rely on Grammarly.

  8. This was fascinating! I kept getting 3 even when trying to count without reading. I subscribed to your blog and look forward to more! Thanks for the fun post 🙂

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