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 Possessive ‘s’ 2 Irregular past 3 Regular third person 4 Present progressive 5 Regular past 6 Regular plural 19-28 25-46 27-33 26-40 26-48 28-50 1 Early III 2 Early I 3 Late III 4 Late I 5 Late II 6 Early II 12-22 27-28 33-34 31-32 28-30 22-26