The Easiest Change (y = ee sound)
Without a doubt, the one change that any modern day user of Ms. Spalding's original curriculum (first published in 1957) should make is to modify the treatment of the endings of words like happy, silly, valley, monkey, collie and lilies. The Writing Road to Reading, through five editions in print so far, has never acknowledged that the endings of many words have a very clear /ee/ sound in them. Instead, parents and teachers are expected to teach children that they actually hear an /i/ sound instead. While it might have been true nearly a century ago that most English dialects pronounce happy as happi, this is certainly not the case today, nor has it been for decades. Furthermore, making the change is simple. Here's all that's involved.
1. Add the /ee/ Sound to Phonogram y
Phonogram y would then be /ee/ie/i/ (happy, shy, gym) with the /ee/ sound taught as the first sound because it is the most common sound for that phonogram.
2. Add the /ee/ Sound to Phonogram i
English has imported a lot of words where the phonogram i represents the /ee/ sound; words such as pizza, taxi and confetti. Plus, in modern English dialects we hear an /ee/ sound in words like happier and happiest. Yet, Ms. Spalding advocated teaching only two sounds for the phonogram i, those being the /i/ sound in big and the /ie/ sound in find.
Phonogram i would then be /i/ie/ee/ (big, find, ski) with the /ee/ sound added as the third sound because it occurs least often.
Note that phonograms y and i each represent the same three sounds, but in reverse order.
3. Drop the /i/ Sound from Phonogram ie
Ms. Spalding's insistence that words like happy end with an /i/ sound rather than the /ee/ sound we all hear (at least today) caused her to add a complication to the phonogram ie because, for the sake of consistency, she then had to conclude that words like collie and lilies also had an /i/ sound. This meant that the phonogram ie had to represent three sounds, the /ie/ in tie, the /ee/ in field, and the /i/ ending in collie and lilies. In fact, the phonogram ie only has two common sounds, /ie/ and /ee/ (tie, field) and can be taught that way without creating any issues.
4. Drop the /i/ Sound from Phonogram ey
In a similar vein, if a word like happy ended in an /i/ sound, then so must words like valley, money and jockey. Therefore, the phonogram ey had to have three sounds as well, /ee/ae/i/ (key, they, valley). But if we simply acknowledge the fact that these words ending in the phonogram ey do have an /ee/ sound, then the phonogram ey also represents only two sounds, /ee/ and /ae/ (key, they) and can be taught that way as well.
The End Result: No Net Change
The result is to add one sound to two phonograms, and drop one sound from two phonograms, resulting in no net change in complexity. More important, the end result would be what children (and their adult teachers and parents) actually hear in the affected words. There are no good reasons not to make these changes and plenty of reasons that they make sense, and should be made. And making the changes is trivial. Just teach the sounds as indicated above.