of the first language on the second is known as negative language transfer. French speakers learning English, however, do not usually make the same mistake of leaving out "it" in "It is raining." This is because pronominal and impersonal sentence subjects can be omitted (or as in this case, are not used in the first place) in Spanish but not in French. The French speaker knowing to use a pronominal sentence subject when speaking English is an example of positive language transfer. Not all errors occur in the same ways; even two individuals with the same native language learning the same second language still have the potential to utilize different parts of their native language. Likewise, these same two individuals may develop near-native fluency in different forms of grammar. Another error that can occur is called language convergence. This can occur for children acquiring a second language. The grammar structures or common grammatical patterns of one language may influence another. In a study, Singaporean elementary school students who were learning both English and Mandarin showed signs of language convergence. In this study, these students showed a preference for using grammatical patterns common in Mandarin when speaking English. Language convergence occurs because the children are not only acquiring the grammar of the new language but still developing the grammar of their native language, so the two grammars converge. Also, when people learn a second language, the way they speak their first language changes in subtle ways. These changes can be with any aspect of language, from pronunciation and syntax to the gestures the learner makes and the language features they tend to notice. For example, French speakers who spoke English as a second language pronounced the /t/ sound in French differently from monolingual French speakers. This kind of change in pronunciation has been found even at the onset of second-language acquisition; for example, English speakers pronounced the English /p t k/ sounds, as well as English vowels, differently after they began to learn Korean. These effects of the second language on the first led Vivian Cook to propose the idea of multi-competence, which sees the different languages a person speaks not as separate systems, but as related systems in their mind. Learner language Learner language is the written or spoken language produced by a learner. It is also the main type of data used in second-language acquisition research. Much research in