Which morpheme is NOT part of Brown's Stage 2 morphemes?

Which morpheme is NOT part of Brown's Stage 2 morphemes?

• A. past irregular (went)
• B. present progressive (-ing)
• C. prepositions on/in
• D. contractable auxiliary

Answer: (A)

Brown's Stage 2 morphemes cover early, productive endings and function-word uses that children typically master around the end of their second year. This set includes the plural -s on nouns (as in dogs), the present progressive -ing to mark ongoing action (as in looking), basic spatial prepositions like in and on, and contractible auxiliary forms (such as it's or they're in simple contexts). The irregular past tense (went, came) isn’t part of Stage 2 because it’s not produced by a simple rule and tends to require memorized, irregular forms learned a bit later. That’s why this option is the best answer: it doesn’t belong to Stage 2, while the others do.

Brown's Stage 2 morphemes cover early, productive endings and function-word uses that children typically master around the end of their second year. This set includes the plural -s on nouns (as in dogs), the present progressive -ing to mark ongoing action (as in looking), basic spatial prepositions like in and on, and contractible auxiliary forms (such as it's or they're in simple contexts). The irregular past tense (went, came) isn’t part of Stage 2 because it’s not produced by a simple rule and tends to require memorized, irregular forms learned a bit later. That’s why this option is the best answer: it doesn’t belong to Stage 2, while the others do.