Table 4.

Hurdle models for the English samples examining predictors of the odds of engaging in any between-utterance and within-utterance code-switching (CS; top) and the frequency of such CS among those children who switch at least once (bottom).

Variable	Between-utterance CS to Spanish				Within-utterance CS to Spanish
	Estimate	SE	χ2	p	Estimate	SE	χ2	p
	Logistic model of odds of engaging in CS
Observations	n = 60 (31 DLD, 29 TLD)				n = 60 (31 DLD, 29 TLD)
Intercept	−1.20	0.54			−0.58	0.42
Age in months (centered)	−0.06	0.06	1.29	.256	−0.02	0.03	0.22	.638
English BESA (group z score)	−1.13	0.45	8.20	.004	−0.73	0.32	5.68	.017
Group (DLD vs. TLD)	−1.19	0.85	2.15	.143	−0.23	0.63	0.13	.715
Spanish BESA (group z score)	0.66	0.38	3.30	.069	0.29	0.30	0.96	.328
Negative binomial count model of CS utterances (out of total utterances) given at least one CS utterance
Observations	n = 13 (10 DLD, three TLD)				n = 21 (12 DLD, nine TLD)
Intercept	n/a (too few observations)				−2.72	0.58
Age in months (centered)					−0.03	0.05	0.33	.566
English BESA (group z score)					−0.99	0.45	4.61	.032
Group (DLD vs. TLD)					0.24	0.62	0.15	.702
Spanish BESA (group z score)					0.61	0.36	2.66	.103

Note. Bold values indicate significant effects based on a likelihood ratio test. To measure proficiency while reducing the confound with diagnostic status, Spanish and English Bilingual English-Spanish Assessment (BESA) morphosyntax standard scores were z scored within each group separately. Coefficients indicate the effect of a 1 SD increase above the mean score within the child's group. DLD = developmental language disorder; TLD = typical language development; n/a = not applicable.