1. You have seen that singular nouns that end with the sounds [s], [z], [ch], or [sh] take the plural suffix -es. An example of another kind of singular noun that takes -es rather than -s is story with its plural stories.
Stories can be divided into the singular noun story plus the suffix -es. But if we just add those two elements together, we get a wrong spelling: story + es = ∗storyes
Here is what really happens: story+ i + es = stories
When we add -es to story, a letter is taken away and another one is put in its place.
What letter is taken away? <y>
What letter is put in its place? <i>−−−−−
When we add the suffix -es to nouns like story, the <y> is replaced with <i>−−−−−
2. The following rule is called the Rule of Simple Addition:
Unless you know some reason to make a change, when you add elements together to spell a word, do not make any changes at all. Simply add the elements together.
Two reasons for making a change when you add elements together are twinning final consonants in words like running (run + n + ing) and deleting final <e> in words like riding (ride+ ing). Changing the <y> to <i> in words like stories is a third kind of change. It is a third case where the Rule of Simple Addition does not apply.
3. Divide each of these plural nouns into its singular noun plus -es or −s. Show cases where the <y> changes to <i>:
= Singular Noun
4. Look at the singular nouns in which the <y> changed to an <i>. Is the letter right in front of the <y> a vowel or is it a consonant? A consonant. Which suffix did they take, -es or −s? -es.
5. Look at the singular nouns in which the <y> did not change to an <i>. Is the letter right in front of the <y> a vowel or is it a consonant? A vowel . Which suffix did they -es or −s? -s.
6. When you make a plural noun out of a singular noun that ends in the letter <y> with a consonant letter right in front of it, you change the <y> to <l> and add the suffix -es.
Word Venn. Inside circle A put only those singular nouns that use the suffix -es to form their plural. Inside circle B put only those singular nouns that end with the letter <y>.
What should you put inside area 2? Singular nouns that use the suffix -es to form plurals and end with the letter<y>. What kind of singular nouns should you put in area 4 outside the circles? Singular nouns that do not use the suffix -es to form plurals and do not end with the letter<y>
Teaching Notes. The change of <y> to <i> is the first instance of the third kind of change—replacement, in which one letter is replaced by another—that can preempt the Rule of Simple Addition. In later lessons students will learn other settings in which the <y>-to-<i> replacement takes place. The replacement occurs because of a fairly strong distribution rule that became established in English by the 17th century: In general, the vowel letters <y> and <i> work together as a team, with <y> occurring in word-final position, <i> in word-initial and word-medial. Thus, when a final <y> preceded by a consonant becomes word-medial with the addition of a suffix, it is replaced with <i>. The replacement does not take place if the <y> is preceded by a vowel because in such cases the <y> is part of a vowel digraph, and digraphs are routinely exempted from such tactical rules. Because of the strength of simple addition in forming compounds, the <y>-to-<i> replacement regularly does not occur inside compound words: ladybug, not *ladibug. For more on the tactics of <y> and <i>, and the <y>-to-<i> rule, see AES, pp. 84-87.