Acquisition of English grammatical morphology was examined in five internationally adopted (IA) children from China (aged 0;10-1;1 at adoption) during the first three years' exposure to English to determine whether acquisition patterns were characteristic of child second language (L2) learners or monolingual first language (L1) learners. Results from spontaneous and elicited speech showed that IA children acquired grammatical morphemes similarly to L1 learners; namely, (1) non-tense-marking morphemes were acquired earlier than tense-marking morphemes; (2) BE was acquired in synchrony with other tense-marking morphemes; and (3) a high percentage of omission errors and a low percentage of commission errors were observed.