Which word correctly completes the sentence? One deer ran; three ran.
- deers
- deeres
- deerS
- deer (correct answer)
Explanation: This tests CCSS.L.2.1.b (forming and using frequently occurring irregular plural nouns like feet, children, teeth, mice, fish). Most plural nouns are formed by adding -s (cats, dogs) or -es (boxes, dishes), but irregular plurals don't follow this rule. Common irregular plurals 2nd graders should know: foot→feet (change vowel), tooth→teeth (change vowel), child→children (add -ren), mouse→mice (change vowel), man→men and woman→women (change vowel), fish→fish and sheep→sheep and deer→deer (no change), goose→geese (change vowel), leaf→leaves, knife→knives, shelf→shelves, and wolf→wolves (change -f to -ves). Students must memorize these because they don't follow the regular pattern. Choice C is correct because "deer" is the proper plural form of "deer." This is a frequently occurring irregular plural that follows the no change pattern. Choice A shows adding -s incorrectly; second graders often try to add -s to all plurals even irregular ones. To help students: Create irregular plural chart organized by pattern: Vowel Change (foot-feet, tooth-teeth, man-men, woman-women, goose-geese, mouse-mice), Add -ren (child-children, ox-oxen), No Change (fish-fish, sheep-sheep, deer-deer), F→V (leaf-leaves, knife-knives, wolf-wolves, shelf-shelves, loaf-loaves). Practice with flashcards: singular on one side, plural on other.