Table 3.

Information about the distribution of obligatory contexts for each morpheme across sentence position and allomorph contexts.

		Medial				Final				All Positions
Morpheme		-s	-z	-iz	All	-s	-z	-iz	All	All Allomorphs
Plural	M (SD)	1.56 (0.73)	2 (1.62)		2.31 (1.74)	2.25 (2.17)	4 (3.15)	1 (0)	4.85 (4.19)	5.9 (5.15)
	range	0–3	0–8		0–8	0–9	0–14	0–1	0–22	0–29
	N	9	23		26	20	44	2	46	48
Possessive	M (SD)	1 (0)	1.92 (1.56)		1.79 (1.48)		4.25 (5.85)		4.25 (5.85)	2.62 (4.38)
	range	0–1	0–5		0–5		0–13		0–13	0–18
	N	2	12		14		4		4	16
Copula	M (SD)	8.02 (6.91)	2.74 (1.83)	3.94 (4.88)	12.56 (10.69)			1.29 (0.76)	1.29 (0.76)	13.26 (11.58)
	range	0–33	0–7	0–25	0–45			0–3	0–3	0–51
	N	49	34	36	50			7	7	50
Auxiliary	M (SD)	2.08 (1.61)	2.59 (2.45)	1.17 (0.41)	2.79 (2.82)					2.79 (2.82)
	range	0–5	0–11	0–2	0–12					0–12
	N	13	17	6	28					28
3rd Singular	M (SD)	1.47 (0.99)	1.56 (0.86)	1 (0)	2.08 (1.63)	1 (NA)	1 (0)		1 (0)	2.11 (1.65)
	range	0–4	0–4	0–1	0–7	0–1	0–1		0–1	0–7
	N	15	18	2	25	1	5		5	27
All Morphemes	M (SD)	9.35 (7.80)	5.44 (4.83)	4.19 (5.05)	16.53 (13.24)	2.3 (2.18)	4.38 (3.51)	1.22 (0.67)	5.52 (4.95)	22.02 (17.25)
	range	0–34	0–21	0–26	1–56	0–9	0–14	0–3	0–23	4–74
	N	49	43	36	51	20	45	9	46	51

Note: The mean (M) and standard deviation (SD) of opportunities was calculated using only those (N) children who had at least 1 obligatory context available. The range includes all children. The distribution of values reflects the natural distribution of contexts in English (e.g., auxiliary is rarely heard utterance finally, even in adult speech).