Relier Pairs Brown’s MLU stagesVersion en ligne Test yourself on Brown’s research on morphological acquisition by matching pairs of morphemes with the month age of mastery. par Som Person 1 Present progressive 2 Possessive ‘s’ 3 Regular plural 4 Irregular past 5 Regular past 6 Regular third person 19-28 28-50 27-33 25-46 26-48 26-40 1 Early II 2 Early III 3 Early I 4 Late II 5 Late III 6 Late I 27-28 22-26 12-22 33-34 31-32 28-30