The article What Are the English Phonemes? covers the sounds of English words. Most phonics programs teach around 43 to 45 phonemes. In this article, we will be discussing how those 40-plus phonemes are represented in print.
Graphemes, Phonograms, Letters, and Digraphs
Each of the above words have one thing in common. They all refer to spellings of phonemes.
Everyone knows what a letter is, although I would estimate based upon my experience with struggling readers, that only about half the 3rd graders in a classroom know that there are exactly 26 of them. Letters are easy.
Digraphs, technically, are pairs of letters that represent a single sound or, more accurately, a single phoneme. For example, sh, th, ow, oy, bb, tt, and nn are usually digraphs when they appear in words. However, I have always used the term digraph to describe any spelling of a phoneme that has two or more letters, so in the OnTrack Reading curricula the igh in fight, the eigh in weight, and the ough in dough are all referred to as digraphs.
As for graphemes and phonograms, they're just terms that mean "letters and digraphs that represent phonemes." Grapheme is the more technical term. I believe the term phonogram was popularized by Romalda Spalding when she presented an excellent phonics curriculum in The Writing Road to Reading in the 1950's. Essentially, then, any letter or digraph is also a phonogram, and also a grapheme. Despite the title of this article, I prefer to use phonogram, which means "picture of a sound" which is exactly what it is.
When it comes to teaching a young child, all you need are three words, sound, letter, and digraph. Sounds make up words, and letters and digraphs represent those sounds on the printed page. Later on, I use phonemes and phonograms, explaining that the first is a word for the sounds and the second is the word for the spellings we are working with in a phonics program.
Selecting the Phonograms to Teach
One overriding objective in the designing of a phonics curriculum is to strive for simplification wherever possible because the curriculum will be directed at five-year-olds and six-year-olds. But English spellings are, frankly, a complicated mess so a lot of decisions have to be made. Those decisions come in two forms.
The first is whether to include a particular spelling in the set of phonograms that need to be explicitly taught during the course of the program. The second decision is what sounds to assign to any particular phonogram.
Consider the first decision. There are probably a couple hundred different spellings of various sounds in English words. But do we need to teach each and every one of them? No, some of them can be discovered by properly-prepared readers as they are encountered. So the challenge is to both limit the set of phonograms to explicitly teach and to decide which ones they should be.
The OnTrack Reading Phonics Programs acknowledge about 105 to 110 phonograms, but explicitly teach about ninety of them. Eighty four of them are included in the Free Phonogram Flash Cards set that you can download at the link. If a young child learned that entire set, he would have a solid base of phonics information to build upon during future reading.
An Example of An Unimportant Phonogram: aigh
As an example of what sort of decisions have to be made, take the example of the /ae/ sound in words like table, chain, pay, and they. Each of those four spellings of the /ae/ sound is worth teaching explicitly because a child will find them useful in decoding many unfamiliar words that he encounters later. On the other hand, the aigh spelling in the word straight appears only in that word, and in derivations like straighten, so it makes no sense to add it to the phonograms for the /ae/ sound that a child should be explicitly taught.
Yes, aigh is a phonogram for the /ae/ phoneme, but the purpose of explicitly teaching the phonograms and associated sounds is to prepare a child to decode unfamiliar words. When the word straight is encountered, just underline the phonogram aigh and treat it as the /ae/ sound, but don't expect to see aigh on any of the 84 OnTrack Reading Phonogram Flash Cards, for a child won't need it for any other unfamiliar words he encounters.
An Example of An Unimportant Sound: The /ie/ Sound of eigh
Now consider the phonogram eigh in the words height and sleight (as in "sleight of hand") with the treatment of the phonogram aigh. The phonogram eigh is indeed a phonogram worth teaching, for it appears in several common words, but in most of those words (eight, freight, neighbor) it's the /ae/ sound. So a child is taught the phonogram eigh, but only as the /ae/ sound. It just doesn't represent the /ie/ sound in enough words to make it worth teaching as the /ie/ sound. Instead, because it's taught as only the /ae/ sound, when height is encountered, the eigh is double-underlined. The double-underline marks it as a very unusual pronunciation for that phonogram.
Summing up the two different situations: Both aigh and eigh are phonograms for sounds in English words, but aigh is found so rarely that it need not be explicitly taught while eigh does need to be taught, but only as an /ae/ sound because it represents an /ie/ sound so rarely. (The word height is probably the only time a younger reader will run into it as an /ie/ sound.)
The Ending Digraphs
While Ms. Spalding's curriculum in The Writing Road to Reading is excellent overall, she made a questionable decision with her treatment of the ending "e" found in so many English words. Ms. Spalding came up with five different reasons for placing an "e" at the end of a word (including rule #5, the "no-job-e", i.e, no reason at all), and in those cases she disregarded the concept of the phonogram as well.
In the OnTrack Reading programs, nine similar digraphs were added to her set of phonograms. They're referred to as "ending digraphs" on the phonogram flash cards and address the code in words like since, lunge, cue, glove, come, done, house, sneeze, and sample. Note that most of those added ending digraphs are simple to learn because they're endings that take the same sounds as the consonant letter in front of the "e." The phonogram se even takes the same two sounds as the phonogram s, the /s/ and /z/ sounds (house, choose). Then, to address the most common case of an ending "e", the term "split vowel digraph" is used, as described next.
Magic-e, Silent-e, Bossy-e, etc.
Perhaps no English spelling convention has generated more curriculum choices than the split vowel digraph found in word like note, flame, here, slide, and cute. With the exception of ae, all of the other spellings are phonograms in common words when not split (toe, heel, pie, cue). Because of that fact, instead of claiming that something "magic" is going on, or that some letters are "silent" (others aren't?), or that the letter "e" gets to be "bossy" for some unexplained reason (because it's last?), all that is required is to explain that the digraphs ee, ie, oe, and ue are often "split" and to introduce the term "split vowel digraph," and then use a few examples to train a child to see the split vowel digraph in words. This is thoroughly explained on the page Explaining Split Vowel Digraphs. Essentially, only the ee, ie, oe, and ue spellings need to be included on the flash cards. They are just split apart in many words, but continue to represent their same sounds. And once a child has learned the concept, the a-e words like flame and trade are easy to add to it.
Simplicity: The Overall Consideration
While it takes a long time, and a lot of words, to describe the logic behind choices made in designing the phonogram set and associated sounds used in the OnTrack Reading programs, the goal was always to achieve the simplest result possible from the point of view of the children who would have to learn the method. Over the course of teaching the first 50 or so of the nearly 200 children I worked with in one-on-one lessons over a decade, the set was fine-tuned, some decisions were reversed, and the present phonogram set was the result.
I'm reasonably certain that if every English-speaking child knew the contents of the 84 phonogram flash cards by age 9 or so, both the reading and the spelling abilities of the overall student population would improve significantly. That's unlikely to happen, but as a parent, you can see that your own children learn them, if you choose to do so. You could use either the complete Advanced Code Workbook or just the Phonogram Flash Cards themselves. All of them utilize the same set of 43 sounds (phonemes) and 84 phonograms (graphemes).