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