Sentence:  Mary Katharine, one of the things in California, kids apparently who speak English as a second language have a year in which they can take classes that are taught in their <WSD>native language</WSD> in addition to English, and some people would say that that should help them really get established and after that, you're on your own, go take all the tests in English. 
Meaning of the word marked with <WSD> tags:  One's first language, learned in early childhood.