My child keeps writing b instead of d. Is that dyslexia?

Almost certainly not on its own. Children commonly reverse letters when they first learn to read and write, including letters whose backwards form is not a real letter at all, and the errors fade as reading gets stronger. Reversals were once treated as a hallmark of dyslexia, but the research on that is genuinely mixed: some studies find more reversals in children with dyslexia, others find little or no difference. What matters is whether reading itself is moving forward.

Should I teach letter names or letter sounds?

Both, and they help each other. For eight of the consonants the name is a direct clue to the sound, because the sound is the first thing you say when you say the name. Children pick those up faster, and they appear to work it out themselves without being told.

Which letters will my child find hardest?

h, w and y, whose names contain no trace of their sound. Then f, l, m, n, r and s, where the sound is buried at the end of the name. The difference is not about how hard the sounds are to say: the researchers checked that, and the three groups did not differ in when children master those sounds in speech.

How do I explain c and k when they make the same sound?

At age four or five, mostly you do not. Both spell the /k/ sound, English has no tidy rule a young child can use, and the workable answer is to teach one of them properly first and let the other join in later. Teaching schemes disagree on the details and no trial we could find settles it.

Why do short vowel sounds come before long ones?

Partly because short vowels turn up in the simplest three-letter words, and partly to avoid a specific muddle: a vowel's long sound is identical to the letter's name. Teach the name and the long sound together at the start and a child has nothing left to hang the short sound on. This is teaching convention rather than a tested finding.

Try a lesson

Research, in plain words

Teaching letter sounds: what the research settles, and what it doesn't

Some letters are genuinely much harder than others, and there is a neat reason why. There is also a straight answer about b and d, which is the question we get asked most.

Names or sounds?

A letter has a name and a sound, and they are not the same thing. The name of b is “bee”. The sound is /b/, a short puff with no vowel hanging off it. Reading runs on the sounds: you cannot get from “bee-ay-tee” to “bat”.

For years the advice swung between the two, with some people arguing names confuse children and should be delayed. The more interesting finding is that names and sounds are not rivals. Children use the names to work out the sounds, and they do it without being taught to.

Why b is easier than f, and f than h

A study of 143 five- and six-year-olds [1] sorted the consonants into three groups by where the sound sits inside the letter's name. The three groups came out in a clear order, every time.

bdjkptvz

Easiest: the sound starts the name

v is called “vee”, and vee starts with /v/. Say the name out loud and the sound is right there at the front, in the spot a young child notices most. These letters go in fastest.

flmnrs

Harder: the sound ends the name

m is called “em”, and the /m/ is stuck on the end. The clue is in the name but buried at the back, where it is easier to miss. Children scored measurably lower on these.

hwy

Hardest: the sound is not in the name at all

h is called “aitch”, which contains no /h/ whatsoever. Nothing in the name helps. These have to be learned outright, and they were the lowest-scoring group of the three.

In the sound test, children did best on the first group, significantly worse on the second and significantly worse again on the third [1]. On the name test the three groups came out level, which is the detail that gives the game away: the difference is about the sound, not about the letters being more or less familiar.

The obvious objection is that /b/ and /v/ might simply be easier sounds for a small child to say than /h/. The researchers checked, using published rankings of when children master each speech sound, and found no meaningful difference between the three groups [1]. So it is not the mouth. It is the name doing the work.

Three honest footnotes to that study

Most of the children had a history of speech sound disorders. That was the point: the researchers wanted to know whether children who struggle with sounds still use letter names this way. They do, and so did the smaller comparison group of typically developing children [1].
Vowels were left out of the analysis entirely, because they do not fit the three categories. A vowel's long sound is identical to its name [1], so it cannot be sorted alongside the consonants. Everything on this page about easier and harder letters is about consonants.
The same paper notes that children in England do not show this advantage [1]. English schools teach letter sounds first and downplay the names, so the children have no name to lean on. The finding describes a group of children taught a particular way, not a fact about the alphabet.

What we do with this: h, w and y get more time and more repetition than b or p, because a child gets no free help from the name. Nobody should be surprised or worried when those three take longer.

The b and d question

This is the one that keeps parents awake, so here is the direct answer first: a young child mixing up b and d is ordinary, and by itself it is not evidence of dyslexia.

Children reverse letters routinely when they first learn to read and write, including letters whose backwards version is not a real letter at all [3], which tells you something. A child writing a backwards J is not confusing it with anything. They have not yet learned that direction is part of a letter's identity, and there is no reason they should have, because for everything else in a child's life direction is irrelevant. A cup facing left is still a cup.

The errors fade as reading gets stronger [3]. On the dyslexia question, the same paper is careful in a way that popular articles are not: reversals were once thought to be a hallmark of dyslexia, but the evidence is mixed, with some studies finding more reversals in children with dyslexia and others finding little or no difference [3].

What we will not tell you

You will read almost everywhere that reversals are normal until age seven. We are not going to repeat that number, because we could not find it in a source we were able to read. What the research we did read says is narrower: the errors are common early on and decrease as reading skill grows[3]. It puts no line in the sand at any birthday.

The study behind that is also small, fifteen children aged five to twelve alongside fifteen adults [3], and worth reading with that in mind.

The practical version: watch the reading, not the reversals. If a child is steadily working out new words and enjoying books, occasional backwards letters are a handwriting habit that will pass. If reading itself has stalled for months, that is worth raising with their teacher, and it would be worth raising whether or not any letters were backwards.

Two things nobody has settled

c and k

Two letters, one sound. English has no rule about which to use that a five-year-old can apply, and the real one (about which vowel follows) arrives years later. Schemes handle it differently, usually by teaching one letter properly and bringing in the other once it is solid.

Short vowels before long

Short vowels come first almost everywhere. The reason usually given is that they fill the simplest three-letter words. There is a second reason worth knowing about, below.

The second reason for short vowels first is a real trap. A vowel's long sound is identical to its name [1]: the letter a is called “ay”, and “ay” is exactly its long sound. Teach the name and the long sound together at the very start and you have given a child one fact twice, with nowhere left to put the short sound in “cat”. Holding the long sounds back until the short ones are solid keeps them separate.

Both of those are convention

The reasoning above is sound reasoning. It is not a tested finding, and we could not locate a trial that settles either question. Teaching schemes broadly agree, which is worth something and is not the same as evidence.

The thing that is established is one level up: teaching in a deliberate order beats teaching letters as they happen to come up, and the main families of systematic approach perform about the same as each other [2]. Whatever the answer to c versus k turns out to be, it is not where the difference between reading and not reading is made.

Questions parents ask

My child keeps writing b instead of d. Is that dyslexia?: Almost certainly not on its own. Children commonly reverse letters when they first learn to read and write, including letters whose backwards form is not a real letter at all, and the errors fade as reading gets stronger. Reversals were once treated as a hallmark of dyslexia, but the research on that is genuinely mixed: some studies find more reversals in children with dyslexia, others find little or no difference. What matters is whether reading itself is moving forward. [3]
Should I teach letter names or letter sounds?: Both, and they help each other. For eight of the consonants the name is a direct clue to the sound, because the sound is the first thing you say when you say the name. Children pick those up faster, and they appear to work it out themselves without being told. [1]
Which letters will my child find hardest?: h, w and y, whose names contain no trace of their sound. Then f, l, m, n, r and s, where the sound is buried at the end of the name. The difference is not about how hard the sounds are to say: the researchers checked that, and the three groups did not differ in when children master those sounds in speech. [1]
How do I explain c and k when they make the same sound?: At age four or five, mostly you do not. Both spell the /k/ sound, English has no tidy rule a young child can use, and the workable answer is to teach one of them properly first and let the other join in later. Teaching schemes disagree on the details and no trial we could find settles it.
Why do short vowel sounds come before long ones?: Partly because short vowels turn up in the simplest three-letter words, and partly to avoid a specific muddle: a vowel's long sound is identical to the letter's name. Teach the name and the long sound together at the start and a child has nothing left to hang the short sound on. This is teaching convention rather than a tested finding. [1]

Keep reading

What the science of reading actually means, including what the effect sizes really say.
The order children learn to read in, and why it is less of a staircase than it looks.

Sources

Every source here was read before it was cited. Follow any number in the text to land on its entry.

[1]Treiman, R., Pennington, B. F., Shriberg, L. D., & Boada, R. (2008). Which children benefit from letter names in learning letter sounds? Cognition, 106(3), 1322-1338. doi:10.1016/j.cognition.2007.06.006
[2]Ehri, L. C., Nunes, S. R., Stahl, S. A., & Willows, D. M. (2001). Systematic phonics instruction helps students learn to read: evidence from the National Reading Panel's meta-analysis. Review of Educational Research, 71(3), 393-447. doi:10.3102/00346543071003393
[3]Blackburne, L. K., Eddy, M. D., Kalra, P., Yee, D., Sinha, P., & Gabrieli, J. D. E. (2014). Neural correlates of letter reversal in children and adults. PLOS ONE, 9(5), e98386. doi:10.1371/journal.pone.0098386