As noted above, the order of acquisition for second language is not
the same as the order of acquisition for first language, but there are
some similarities. Table 2.1, from Krashen (1977), presents an average

TABLE 2.1. “Average” order of acquisition of grammatical morphemes for English
as a second language (children and adults)

Notes:

1. This order is derived from an analysis of empirical studies of second language acquisition
(Krashen, 1977). Most studies show significant correlatons with the average order.

2. No claims are made about ordering relations for morphemes in the same box.

3. Many of the relationships posited here also hold for child first language acquisition, but some do
not: In general, the bound morphemes have the same relative order for first and second language
acquisition (ING, PLURAL, IR. PAST, REG. PAST, III SINGULAR, and POSSESSIVE) while
AUXILIARY and COPULA tend to be acquired relatively later in first language acquisition than
in second language acquisition.

Full of holes, but interesting.