It has been argued extensively that children acquiring a second language (L2) simplify the target sounds of that language using the same phonological processes as children use in acquiring their first language (L1) (cf. Hecht and Mulford 1982; Piper, 1984a, 1984b; Garnica and Herbert 1979). Since these processes are generally thought to be universal, it is not surprising that this should be the case. Nevertheless, there are differences between L1 and L2 learners both in the simplification processes they use and in the way they use them. Some processes do not appear at all or appear unsystematically in L2 learners; some processes are retained much longer by L2 learners than would be expected given their early disappearance in L1 learners. In this paper, I take a closer look at the incidence, duration and systematicity of these processes in the developing phonology of ten ESL children, and attempt to demonstrate some ways in which normal acquisition of the L2 sound system by children differs from first language acquisition.