What is the “C Rule” in phonics?

The other day I came across an article about the Pacific Ocean and it occurred to me that the letter “c” has 3 different sounds in that name.

How is a student learning to read supposed to know which “c” sound to use for each occurrence of the letter?

Traditional phonics instruction tells kids to use the “Rule of c” which is:

  1. the letter c produces the /s/ sound, as in “silly” if it is followed by the letters ‘e’, ‘i’, or ‘y’. For example: cent, city, and cylinder. This sound is known as the “soft c” sound, and
  2. the letter c produces the /k/ sound, as in “king” if it is followed by the letters ‘a’, ‘o’, or ‘u’ or a consonant at the end of the word. For example, car, coat, and across. This sound is known as the hard c sound.

So how does this rule work out in real life?

Well, for starters, there are instances where, according to the rule, a “c” should be a “soft” but is “hard” instead, such as the word “syncing.” There are also instances where the “c” should be “hard” but is “soft” instead, such as the word “facade.”

But this really just scratches the surface of the problems with the C Rule. Because the letter “c” by itself actually has 5 sounds. These are:

  • /k/ as in “cat”
  • /s/ as in “city”
  • /sh/ as in “ocean”
  • /ch/ as in “cello”
  • /ts/ as in “council”

But wait, there’s more!

The letter “c” can also be combined with other vowels and consonants to produce even more sounds:

  • ‘cc’ can be /ks/ as in “accident”
  • ‘ch’ generally represents /tʃ/ as in “church” BUT it can also have the /ʃ/ sound from French as in “machine” AND it can also have the /k/ sound as in “school” AND it can also have the /kw/ sound as in “choir.”
  • ‘ck’  has the sound /k/, as in “duck.”
  • ‘sc’ has the sound /s/ as in science BUT if you add an “h” it becomes a /k/ sound as in “school” AND it can also have the /sh/ sound as in “schadenfreude.”
  • ‘sci’ can have the /s/ sound as in “science”, BUT it can also have the /ʃ/ sound and in “conscious.”
  • ‘cqu’ has the sound /k/ as in “racquet,” BUT it can also have the /kw/ sound as in “acquire.”
  • ‘cio’ has the /ʃ/ sound as in “delicious.”

… And I’m sure I’m forgetting some.

Phonics has a lot of rules. Almost 600 of them. These “rules” are used to try and make sense of English spelling, which is famously nonsensical. This is why Nobel Prize winning physicist and German immigrant Albert Einstein famously said, “I cannot write in English because of the treacherous spelling. When I am reading, I only hear it and am unable to remember what the written word looks like.”

The problem with phonics rules – aside from the impossibility of remembering them – is that they all have exceptions, and in some cases, they have more exceptions than applications.

Professor Theodore Clymer from the University of Minnesota studied phonics rules and published his results in a paper entitled “The utility of phonic generalizations in the primary grades.” Clymer collected 121 commonly used phonics rules. Using 2,600 words found in basal readers and Merriam-Webster’s Dictionary pronunciation guide, he compared the actual pronunciation of each word to the phonics rules that should apply and calculated a percentage of agreement. Eliminating any rules that did not apply to more than 20 words, Clymer whittled his list down to 45. Then, using 75% as a reasonable level of utility, he found that only 18 of the 45 rules had any utility at all. For example, Clymer found that the generalization commonly referred to as “when two vowels go walking” is effective only 45% of the time.

So you see how complicated using phonics can be. This is why studies have consistently shown that while students need to learn how written language assigns letters to sounds, to become successful and fluent readers and writers of English, students need more than phonics alone (added components that aren’t needed to learn how to decode nearly perfectly phonetic languages such as Italian). That’s why Reading Kingdom includes these other approaches to create a complete system for teaching decoding and comprehension.