I report three experiments that examined whether bilingual speakers sometimes use the grammar of one language and the words from the other language. In the non-switch conditions in experiment 1 and 2, participants described pictures using nouns and adjectives from the same language. In the switch conditions, they used nouns and adjectives from the other language. In Experiment 3, in the switch conditions participants used only the adjectives of noun phrases from the other language. In the non-switch conditions, they used both nouns and adjectives from the same language. I manipulated whether they sometimes used the syntactic properties of adjectives from the other language. The results showed that both grammars of the two languages were activated during bilingual language production. The effect of the grammar of the other language increased in the switch conditions. More inappropriate responses observed when switching from bilinguals’ L2 to L1. I interpret the results in terms of Hartsuiker and Pickering’s (2008) integrated model of syntactic representation.