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