C or k at the start of a word

When does the rule apply?

C is the default spelling for /k/ at the beginning of a word, and our counts show it: the c tables below run into the hundreds while the k tables hold a handful. K steps in only where c would change its sound. Before e, i or y, c says /s/ (cent, city, cycle), so a word that starts with /k/ before those letters needs k: keep, kid, kite. That makes this rule a partner of the soft c rule, and it helps to teach the two in the same week.

Words that follow the rule

Words that break the rule

None. No public word in our lexicon breaks this pattern.

How do you teach it?

Teach it once students read short vowel words with c and k. Write "_at", "_ap", "_id" and "_ept" on the board and ask which letter starts each word. Then remind them that c before i says /s/, so "cid" would read as "sid". Students work out the reason for k themselves, and they remember a reason longer than a rule handed to them.

"We want to write 'kit'. The sound after /k/ is /i/, spelled i. If I wrote c-i-t, the c would say /s/ and we'd read 'sit'. So we need k. Now 'cot'. After /k/ comes o. C before o says /k/, so c it is."

What is the common error, and the fix?

Students who learn k first write "kat", "kup" or "klap". Students who learn c first write "cid" or "cing". The fix: name the letter right after /k/ before writing. If it is e, i or y, use k. Otherwise c is the safe choice, and the exceptions table shows how rare the other cases are.

Sort it: a hands-on activity

Make cards for c and k words and two headers. Add a third pile, "c says /s/", with cent, city and cycle. Students sort, then explain why the third pile proves the k rule: it shows what c does before e, i and y.

How this list was built