Which morphemes characterize Brown's stage 5?

Which morphemes characterize Brown's stage 5?

• A. contractable/uncontractable auxiliary; contractable copula; 3rd person regular/irregular
• B. present progressive -ing; on/in
• C. articles; past regular
• D. uncontractable copula; past irregular

Answer: (A)

The main idea here is that Brown’s stage 5 marks a leap in how children mark tense and agreement, specifically with be and with third-person singular verbs. At this stage, children start using both contracted and uncontracted forms of the verb be as both an auxiliary and a copula, and they begin to attach the third-person singular -s to verbs, including both regular and irregular forms. So you’ll hear combinations like He’s going or He is going (contracted and uncontracted auxiliary) and forms such as She walks, She does/She has, showing the growth of tense marking and agreement that characterizes this late stage. The other options pull in morphemes that appear earlier in development or don’t capture the defining pattern of this stage. Present progressive -ing and prepositions like in/on show up earlier, as do articles. Past regular is present earlier as well and, by itself, doesn’t define stage 5. A mix like uncontractable copula with past irregular blends elements from different stages more than it highlights the specific late-stage pattern of contractible/uncontractible be forms plus 3rd-person singular marking.

The main idea here is that Brown’s stage 5 marks a leap in how children mark tense and agreement, specifically with be and with third-person singular verbs. At this stage, children start using both contracted and uncontracted forms of the verb be as both an auxiliary and a copula, and they begin to attach the third-person singular -s to verbs, including both regular and irregular forms. So you’ll hear combinations like He’s going or He is going (contracted and uncontracted auxiliary) and forms such as She walks, She does/She has, showing the growth of tense marking and agreement that characterizes this late stage.

The other options pull in morphemes that appear earlier in development or don’t capture the defining pattern of this stage. Present progressive -ing and prepositions like in/on show up earlier, as do articles. Past regular is present earlier as well and, by itself, doesn’t define stage 5. A mix like uncontractable copula with past irregular blends elements from different stages more than it highlights the specific late-stage pattern of contractible/uncontractible be forms plus 3rd-person singular marking.